Visual Studio 2013 Database Project: Item Templates with VSIX

Visual Studio 2013 Database Project: Database Item Templates with VSIX

Overview

Strictly speaking VSIX is not a database project or related in kind, but by virtue of Item Templates.  With VSIX projects and the TemplateBuilder (NuGet) package, templates can be built from the contents of an ItemsTemplates folder.  The latter (if not created by TemplateBuilder) should be manually created as ItemTemplates folder as an item of the VSIX project.

NOTE: SQL Server (database) templates are not supported in Visual Studio 2013 VSIX and requires a manual effort to install on a developer’s IDE.  As indicated by the error item below, if the database files added to a VSIX project are changed to have a vstemplate file extension the compiler (on build) should issue this error saying that only CSharp and VBasic templates. Similarly if a Reference is added in the Asset tab of the manifest, the error The targer “TemplateProjectOuputGroup” does not exist in the project” is presented.

VS Database Template Support

VS Database Template Support

VSIX Template

The VSIX project template is available from the Visual Studio 2013 SDK and found under the menu: [Visual C#] >> Extensibility >> VSIX Project.

Template Builder

The TemplateBuilder package is installed from the Package Manager console or from Visual Studio: Tools >> NuGet Package Manager >> Package Manger Console.  Once installed, template are built to the folder: <Drive:>:\Users\<User>\Documents\Visual Studio 2013\Templates\ItemTemplates and <Drive:>\Users\<User>\Documents\Visual Studio 2013\Templates\ProjectTemplates.

NuGet Package Manager

Download and install the NuGet Package Manager for Visual Studio 2013.  It has a VSIX extension but installs by double-click and run.

SideWaffle

SideWaffle is a template pack that adds a selection of project and item templates to Visual Studio, including enabling templates to use for creating new ones. A VSIX project generates an experimental invocation of Visual Studio in which to test these templates so that the real instance is not affected.  To configure templates require a work-flow that is enabled by a separate application (that you create) to populate template and custom parameters when creating a new item.  This article, for now, mentions it but is not using it to create templates.

Create a New VSIX Project for Template Deployment

In order to author customised solutions, projects, code-snippets, and templates, a VSIX project is required.  Depending on the user-environment set-up for Visual Studio, file paths may vary slightly.

Create a new project:

  1. Follow the path: File >> New Project >> [Custom Path] >> [Visual C#] >> extensibility >> VSIX Project
  2. Provide a name for the project and check the solution details
  3. Fill out the VS VSIX Manifest with the appropriate details (reference)
  4. Install the TemplateBuilder package.
VS VSIX Manifest

VS VSIX Manifest

Installing TemplateBuilder

This installation requires the Package Manager Console (NuGet):

  • Follow the path: Tools >> NuGet Package Manager >> Package Manager Console.
  • Type Install-Package TemplateBuilder -Pre at the PM> prompt and hit [Enter].  NOTE: Internet access to https://www.nuget.org/api/v2/ is required.
VS Package Manager Console

VS Package Manager Console

The TemplateManager installation responds favourably on completion of the install, if it succeeds.  NOTE: The NuGet package is downloaded into the file location: <Drive>:\Users\<user name>\AppData\Local\NuGet\Cache and in the event of not having the default Internet location (https://www.nuget.org/api/v2/) available, Visual Studio looks here for whatever the package is being installed.

VS NuGet Installation of TemplateBuilder

VS NuGet Installation of TemplateBuilder

The installation process deposits an example template into: <Drive:>\Users\<User>\Documents\Visual Studio 2013\Templates\ProjectTemplates.  NOTE: there may not actually be an example template in this folder.

Create a Template Solution and Project

The Visual Studio Solution should contain the VSIX project as well as other projects, i.e. those used in which to create the templates.  For example, to create database templates a database project is added to the solution and the corresponding templates with parameters created in there.  This article uses the template created in a previous post (Visual Studio 2013 Database Project: Create a Stored Procedure Item Template) to illustrate how the VSIX project functions in this respect.

There are two methods:

  1. Exporting and importing a template (zip file)
  2. Referencing the template source project from the VSIX project where they are in the same solution

The latter (point 2) does not work for database templates

Exporting the Template

The template (or stored procedure created in the templates project) is created by exporting the necessary file (the actual stored procedure and any referenced files in the case of a project or c# type template) to the folder: <Drive:>\Users\<User>\Documents\Visual Studio 2013\My Exported Templates.  Follow the next steps to affect this:

  • Create, for example a stored procedure template (reference the above link on how to do that) an File >> Export Template >> Item Template, select the correct project, i.e. the database project containing the stored procedure created.
  • Select the correct stored procedure and complete the wizard.  The output template is locatable in the folder: <Drive:>\Users\<User>\Documents\Visual Studio 2013\My Exported Templates in a file called: <Template Name>.zip.

NOTE: Edit the MyTemplate.vstemplate file (contained inside the zip file) in Visual Studio and add an element TemplateGroupID (depicted in the code below) between the templateData tags to help with the filtering of template in the New Item dialog (reference).

VS Template Projects and Item Template

VS Template Projects and Item Template

1
 <TemplateGroupID>Database</TemplateGroupID>

The Item Template (Stored Procedure) is added to the VSIX project.  Use the .vsixmanifest file and add an Itemtemplate item to the Assets tab. Add a:

  • New item,
  • Pick ItemTemplate and
  • Point the File Location to the folder where the copied template zip file has been placed.

NOTE: The path could be: :\Users\\Documents\Visual Studio 2013\Templates\ItemTemplates\\Database\Programmability, but it is up to choice.  However, Visual Studio, on starting up, reads from this location on a user-instance, i.e. local machine.  The project is appended with a new folder, i.e. ItemTemplates and the zip file is appended.

On the  the property of the newly added template (zip) file, set the property Copy to Output Directory is set tot Copy Always.

NOTE: To inspect the XML code of the project file: right-click >> Remove and then right-click >> edit) reveals this setting in its XML structure, as depicted below.

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    "ItemTemplates\Samples\StoredProcedure.zip">
      Always
      true
    
    "packages.config" />
    "Properties\template-builder.props" />
    "source.extension.vsixmanifest">
      Designer
    
  

NOTE: Turn off the Build and Deploy options in the Configuration Manager for the VSIX project.

Using a Reference to the Template Project in the same Solution

A reference to the template project (the one where the stored procedure is authored) is added to the Reference of the VSIX project by using the source.extension.vsixmanifest file’s Assets tab, as before.  But, in this case, the reference is to a project in the same solution.  The fields [Type],

[Source], and [Project] are completed, with project being the name of the said template project.  This adds a reference to the VSIX project.

Set the Properties of the reference (see how), especially the VSIX Sub Path that determines where the template is installed on the menu-tree of the New Item menu function.

NOTE: Visual Studio does not provide a project template for creating database objects, so it seems the export method is the only way in which to get the zip file into the VSIX for deployment.  This aspect may be resolvable by creating the zipped files in a database project and let the project zip them like the wizard and place in the appropriate folder.  Not yet sure how to do this.

Build the Project and Install the Templates

The VSIX project is built and it copies the template zip file to the output folder: \Users\\Documents\Visual Studio 2013\Projects\\\bin\Debug as a .vsix (installable) file along with a TemplateBuilder.dll and the folder structure (Visual Studio) that contains the actual template file.

NOTE: For developer projects, this installation file should be made available on a network shared drive and installed as updates are made, or from a Private Gallery reference) that notifies users via RSS feeds of new extensions.  Alternatively the same file can be uploaded to the Visual Studio Gallery for community consumption and addition.

file in the VSIX project to set the [Assets] by creating a new reference to an ItemTemplate of a project (the one containing the stored procedure template) that also adds it to the References of the VSIX project. Here the Properties of the added assembly can be altered to achieve a variety of things. See the screen image (below) for a visual explanation of what is described.

VS VSIX Template Database Item Folder Location Reference

VS VSIX Template Database Item Folder Location Reference

Executing the <Name>.vsix (installable) file invokes all the things that were set in the manifest to install the template(s).  These are available in Visual Studio and can be inspected via: Tools >> Extensions & Updates >> Templates
, illustrated below.

VS Extensions and Updates Templates folder

VS Extensions and Updates Templates folder

Using the newly installed Templates

After installing the VSIX template package and verifying the extension is in Visual Studio, the template can be used from which to create Projects or Items.  During the installation the templates are deployed to a random folder: %LocalAppData%\Microsoft\VisualStudio\12.0\Extensions and by virtue of %LocalAppData% it only applies to the current user.  Alternatively, setting the manifest to AllUsers=true the extension is installed under Common7\IDE\Extensions (where VS is installed) and appears to all users on the computer (reference).

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Visual Studio 2013 and Database Projects: Create a Database Project with Folder Structure

Visual Studio 2013 and Database Projects: Create a Database Project with Folder Structure

Overview

Data base projects in Visual Studio is a bit of an after thought on application development.  It started with Gert Drapers (the data dude) and became SSDT (SQL Server Data Tools) that had to be installed (as an add-on) to Visual Studio.  This had some varying function over the years, but was aimed at reducing the difficulty of database development in Visual Studio and keep database changes in synch across a solution (matching database and application versions) and multiple server environments through the application life-cycle.

Creating a Database Project

This is quite easy using Visual Studio 2013.  On the first landing page (can be turned off) a Start section has the option from which to create a new project, or the traditional FILE menu is just as simple.

Visual Studio for Database Development First Screen

Visual Studio for Database Development First Screen

VS Create New Database Project Dialog

VS Create New Database Project Dialog

Be mindful that if a project is created and Team Foundation Server (TFS) is being used to take care of how the solution and projects contained by the solution are demarcated.  It is not in the scope of this article to explain how to do this, but suffice to say that where solutions are stored separately from projects, to first create an empty solution and check it in.  Then the projects that are added back to the solution so that all are checked into TFS in their correct locations.

Further take not of the Visual Studio boxes, viz. Solution Explorer, SQL Server Object Explorer, and Properties for example.  These should be orientated (docked) in positions that make sense, I.e. for easy reference.  Below is an example of an instance that contains a Solution with three projects.

VS Database Project Screen

VS Database Project Screen

The two most important boxes are the Solution Explorer and the SQL Server Object Explorer.  The former depicts the Solutions and the database projects.  Where no database actually exists (this is where you create it) SQL Server Objects can be created/ added to the project, or (where a database already exists) imported by a few means.  The first is using a DACPAC (SQL Server Data-tier application extract file), or connecting directly to a SQL Server database, or create one using a script file containing all the object definitions.

Choosing a Folder Structure

Importing a database allows for the folder structure in the project to be changed.  The project folder structure should allow for ease of maintenance and readability.  The folder structure does not influence deployment.

VS Database Project Import Dialog Folder Structure

VS Database Project Import Dialog Folder Structure

An import of an existing database (where no structure is chosen, or defined dumps all files in the root of the project, which is moderately messy, so it must be carefully considered.  A folder is not created where an imported database does not have objects, e.g. Stored Procedures.  If subsequent objects are required, the folder will first have to be created.

Organising the database advances readability, consequently also maintenance, because developers are able to find things quicker.  Any database objects without any discernable grouping are dumped in the root of the project on import.

NOTE:Things that impact the display of objects and what access rights are differentiated in practice, bears on the configuration of the naming scheme.  Making use of database schemas (to group objects and assign login permissions) is an effective strategy for data architecture over using prefixes on objects like sp or pr for a Stored Procedure (source).  The folder structure in Visual Studio and SQL Server Management Studio already informs the object type and with an added schema denotes an organisational name space for such objects.  SQL Server uses a four-part naming scheme: Server.Database.DatabaseSchema.DatabaseObject.  Objects in a schema are owned by the security principle that owns the schema and a schema can contain objects owned by different users.  Any predefined schema (dbo, sys, etc) can be dropped from the model database if not required consequently preventing them from being created in new databases.  A schema owner can be changed without breaking the code, but if an object owner, say Tommy.Object is removed, an ownership change must first be performed before Tommy’s account can be deleted.  However, any fully qualified references will break in the code, e.g.  Server.Database.[tommy[.DatabaseObject. The default dbo schema is owned by the dbo user. Users assigned to the dbo schema do not inherit dbo user account permissions, but the database objects contained in the schema (source).  Using dbo as the owner of all object can greatly simplify managing objects (source).

Previous article (1) [Installation]. . . Next Article (3) [Working the Project]

Visual Studio 2013 and Database Projects: Installation

Visual Studio 2013 and Database Projects–Installation

This installation is for Visual Studio Premium.  Once the image is mounted, the folder contains the installation file for the install, i.e. vs_premium.

VS Premium Folder

VS Premium Folder

Execute the vs_premium file and agree to the License Terms and Privacy Policy, and the location of the installation. Two options are quite important:

  1. Light Switch
  2. Microsoft SQL Server Data Tools

Light Switch is a technology to shorten the development time on business applications and data services for data-centric business applications.  SQL Server Data Tools are the add-on previously (VS 2012) downloaded and installed separately, but now part of the install.  It provides database schema modelling and support for querying live databases.

The other default option is Blend, a visual user-interface design tool using XAML (web) and WYSIWYG (desktop), before part of the Microsoft Expression Studio toolset.  This is not a database specific tool.

Once installed (it takes a while) the Microsoft Account Login dialog is presented for which you are required to have credentials.  Either use an existing account or create one (reference) and then associate an MSDN subscription (licenses that your company pays for) to this identity. Note: a licence key may also be used if you don’t have an MSDN subscription to activate the software (see how).

Microsoft Account Login

Microsoft Account Login

Once logged in access your account details to find the MSDN section where the Subscriber ID and company email are used to link the MSDN profile to the Microsoft User Identity.

Once the subscription is activated the software is licensed.

MSDN Subscription Activation Dialog

MSDN Subscription Activation Dialog

Visual Studio starts with an environment set-up that can be changed at a later stage also.  Here the Database environment (as that is the purpose of this instance) is selected and the colour scheme of your choice.

VS Environment Set-up Dialog

VS Environment Set-up Dialog

This is the installation process and you have arrived at the first screen.

Visual Studio for Database Development First Screen

Visual Studio for Database Development First Screen

Next article in series. . . 2 [coming soon]

Navigate. . . Next Article (2)

Visual Studio 2010/ 2012: Model and Query Database Objects

Introduction

Executing a Visual Studio Database Project’s queries against an existing database, is somewhat different between the two versions, viz. Visual Studio (VS.) 2010 and 2012.  It is slight but useful to consider, after updating both versions to the latest version of SQL Server Data Tools, to see what these are.  This article is not an exhaustive account, but endeavours to jump-start a database developer on the differences.

Prerequisites

Software Versions

Visual Studio

The version of Visual Studio 2012 is upgraded to Service Pack 1 [1, 2], and all references to functionality is relative to that version.

NOTE: Remember to stop any anti-virus software before running the service pack, otherwise the error: “Access is denied” is presented.  The file name of the update is: vsupdate_KB2707250.exe [2], with the updated (after installation) build number:  04940-004-0038003-02092 .  It takes just under forty five minutes to complete.

NOTE: Ensure that the latest SQL Server Data Tools (for Visual Studio 2012) is installed, after this update [5].  If not, an incompatibility message is displayed by Visual Studio on the SQL Server Object Explorer tab, where database connections are listed.  The update installation takes about ten minutes, with the build number updating to: 11.1.21208.0.  After about seven minutes the installation dialogue hangs for a few minutes, with all the bars green, don’t kill it, it will complete.  The same applies for Visual Studio 2010, with build number: 10.3.21208.0, to download from the same location.

Microsoft SQL Server

The version of the installed 2012 database, is upgraded to Service Pack 1, bringing it to build: 11.0.3000.00.  The name of the image file is: en_sql_server_2012_sp1_x86_x64_dvd_1176976.iso, which is obtainable from your MSDN subscription.  NOTE: Remember to turn any anti-virus software off, as explained above.  The installation stalls for a bit, giving no indication that it is actually still running, however, a process called scenarioengine.exe (Windows Task manager) is active, and associated with the currently running update.  A few minutes later (with scenarioengine.exe resting on a zero percent CPU utilisation), a window suddenly pops up.  The SQL Server 2012 Service Pack 1 pop-up, should execute the update for all installed features, after agreeing to the licensing stop.  It takes about an hour.

For SQL Server 2012, the table below provides a list of updates at the time of writing.  NOTE: See the citation [3] on how to determine the installed version, and get to the latest update(s) on the web.

Build Knowledge Base (KB) Description URL Date Released
 11.0.3000.00  KB2674319  Service Pack 1  http://support.microsoft.com/kb/2755533  09 November 2012
 11.0.2383.00  KB2758687  Cumulative Update 4  http://support.microsoft.com/kb/2758687  15 October 2012
 11.0.2332.00  KB2723749  Cumulative Update 3  http://support.microsoft.com/kb/2723749  31 August 2012
 11.0.2325.00  KB2703275  Cumulative Update 2  http://support.microsoft.com/kb/2703275  18 June 2012
 11.0.2316.00  KB2679368  Cumulative Update 1  http://support.microsoft.com/kb/2679368  12 April 2012
 11.0.2100.60  na  SQL Server 2012 RTM  na  06 March 2012

NOTE: Visual Studio can install a SQL Express database known as LocalDB, so that a separate instance of SQL Server does not have to be maintained by developers on their machines [4].

The Problem

Tool-bars, Commands, and going about functionality differ slightly between Visual Studio versions (for database developers), potentially making the navigation an unfamiliar experience.

The Solution

Provide examples of how a database can be accessed, using Visual Studio 2012, in comparison with the older 2010 version, of the development environment, to accelerate the learning experience.

Model and Query Database Objects in Visual Studio 2012

Because we have just moved from Visual Studio 2010 (or having never used Visual Studio, but SQL Server Management Studio) for database development, it is expedient to know the differences and consequential enhancements, when working with a database.

To model or query database objects, as in SQL Server Management Studio, using Visual Studio, is accomplished in several ways.  A designer or query can be used to create and/ or change database objects.

Visual studio can connect to a database, without having a database project open, to view and change objects on the database.  With a project opened, objects can be maintained (in the project tree) while being connected to the database.

The experienced difference, between just working on a database through Visual Studio, or working on a database through Visual Studio’s Database Project, lies in the connection state to the database.  The latter is implicit, by means of the project’s properties, and the former explicit, by connecting to a server and database for the purpose of executing queries that could perform various tasks.

[SQL] Server [Object] Explorer

This function can be used without having a database project open, and also on the side, when working with an open project.  A database structure-tree, similar to that in SQL Server Management Studio, presents itself in the navigation pane of this function.  Commands can be issued, from this pane, against objects in the database.

[SQL] Server [Object] Explorer is a tab that is accessed from the menu tool-bar, or by short-cut key (for both VS. versions–with square brackets denoting the VS. 2012 variance in the name), as follows:

  • View >> Server Explorer
  • Ctrl+Alt+S

From the [SQL] Server [Object] Explorer tab, a new connection is added:

Visual Studio Server Explorer Comparison

Visual Studio Server Explorer Comparison

Visual Studio 2010
  • Use the menu path (from the right-click menu on Data Connections):  Add Connection, or
  • Use the Visual Studio 2010 Add Connection icon
Visual Studio 2012
  • User the menu path  (from the right-click menu on SQL Server): Add SQL Server, or
  • Use the Visual Studio 2012 Add SQL Server icon

NOTE: The dialogue, by which the connection is facilitated, looks different.  Visual Studio 2012 uses the same connection as is used by SQL Server Management Studio.

Once a connection is made to a database, it is listed in the [SQL] Server [Object] Explorer tab, and can consequently be accessed via Visual Studio.

The functionality, hanging off the navigable database objects-tree, is limited to specific database operations relative to the meaningfulness of the node.  Each node in the tree, for example the Databases or Tables nodes, have different menu options onthe right-click menu.  It makes sense when right-clicking a database node that the New Query option would be presented, as opposed to right-clicking a table name where Data View, Code View, and the likes, are presented.

Visual Studio 2012 SQL Server Object Explorer Query

Visual Studio 2012 SQL Server Object Explorer Query

A database query, just like using SQL Server Management Studio, can be created from the SQL Server Object Explorer’s connection to the database, by selecting the appropriate node, viz. SQL Server or Database, using the right-click menu: New Query… to create a query tab.  This query is a bona fide database query, without any context to an object residing in a project, it could perform any database action.

Doing the same in Visual Studio 2010, having the latest version of data tools installed, produces different results.  The New Query option launches a designer view (something like that of Access, or the Database Diagram option) from which to select tables that are to be included in the TSQL query, and restricts, or boxes the developer into a template ability.

Visual Studio 2010 Data Connections Query

Visual Studio 2010 Data Connections Query

Database Diagrams are not present in the Visual Studio’s SQL Server database hierarchy tree, any-more [6], with 2012.  It can still be found in Visual Studio 2010, but only used on databases up to SQL Server 2008.  This is a bit sad, because in my humble opinion, making Visual Studio a one-stop-database-design-shop fails here, because one would really benefit from being able to model a database in the IDE, along with the other functionality.  There is also no modelling option under the Architecture tool-bar option, which leaves SQL Server Management Studio [7] and Visio, as readily available Microsoft modelling tools.

The New Query, accessed from the right-click menu, on a table node (Visual Studio 2010) also launches the designer for a  selection of tables to participate in the query.  Visual Studio 2012 provides: View Code, Designer and Data options, but no New Query.  It does not enable the data-connection tool-bar, showing the database to which the connection points, but implicitly connects to the database to which the object belongs.  This makes sense, because the table is situated within a database, so it goes without saying, but boxes the developer into a view state, when accessing the database from this angle.  But, don’t lament, because when using the added Script-As option, the table’s DDL TSQL is scripted to a new query window (an explicit connection), with the associated tool-bar indicating the database connection, and execute options.  Visual Studio 2010 only provides the boxed-in (implicit) query window for database objects.

NOTE:  To execute an open query, where the Execute icon is presented in a tool-bar (explicitly connected), the short-cut commands and icons are different between versions.

  • Visual Studio 2010: Visual Studio 2010 Query Execute Icon or the short-cut code Ctrl+R
  • Visual Studio 2012: Visual Studio 2012 Query Execute Icon or the short-cut code Ctrl+Shift+E

The Visual Studio 2012 icon is similar to the familiar: Start Debugging (F5) of 2010, which is Execute in SQL Server Management Studio (haven’t we all done that?) and has been changed with a drop-down listing Execute or Execute with debugger (Alt+F5), in 2012.

NOTE: Ctrl-R does not minimise the results-pane, as in SQL Server Management Studio.  Use the key-combination Ctrl+D, R, lifting finger off the Ctrl, after pressing D, to press R.  This however keeps the results pane hidden on next execution, and is brought up again, by repeating the command, hum-ho.

Visual Studio 2012 Query Execution Options

Visual Studio 2012 Query Execution Options

The Programmability (Stored Procedures and Functions) menu option in Visual Studio 2012, provides the Script-As and View Code options.  The latter, by virtue of the word View, provides a View only (implicit connection), i.e. it does not connect to the database for manipulation.  The former Script-As (to new query window) connects to the database for manipulation (explicit connection), i.e. it provides the ability to CREATE the object, i.e. execute the DDL on the database.  In Visual Studio 2010, stored procedures can’t be executed or scripted in the same manner, but only an Add option is provided for a new object.

Using Database Project Objects, connected to a Database

Selecting objects from the Solution Explorer (Visual Studio 2012) opens up the object’s code and design-view, in a non-connected (implicit) state.  However, the project is bound to a database, as specified in the Project Properties tab >> Target Connection String, i.e. implicitly.  When a project database object is displayed, a connection to this database is achieved by right-clicking the code window and selecting: Connection > Connect.  To consequently run the code, on the database, from the same menu, select: Execute, or use the short-cut keys: Ctrl+Shift+E.  The same functionality exists for Visual Studio 2010’s Database Tools.

For a more detailed overview, on working with Visual Studio 2012 Database Projects, view the article: Visual Studio 2012 Database Project (SSDT): Working with a Database Project.

Citations

No. Author Web Site Name URL Date Authored Date Cited
 1.   Kathleen Richards  Visual Studio Magazine  http://visualstudiomagazine.com/articles/2012/11/26/visual-studio-2012-update-released.aspx  26 November2012  07 January2013
 2.  Microsoft  MSDN  http://www.microsoft.com/visualstudio/eng/downloads#d-visual-studio-2012-update  November 2012  07 January2013
 3.  Microsoft  Download Center  http://www.microsoft.com/en-us/download/details.aspx?id=35575&utm_source=MyTechMantra.com  November 2012  07 January2013
 4. sqlexpress SQL Server Experess WebLog http://blogs.msdn.com/b/sqlexpress/archive/2011/07/12/introducing-localdb-a-better-sql-express.aspx 12 July 2011 07 January2013
 5. Microsoft Data DeveloperCenter http://msdn.microsoft.com/en-US/data/tools.aspx December 2012 07 January2013
 6. MSDN Forum MSDN:Visual Studio 11 Database Diagrams http://social.msdn.microsoft.com/Forums/en-US/vstsdb/thread/34154fdf-d81c-4d58-abf4-c27b157dd420 01 April 2012 07 January2013
 7. MSDN MSDN:Visual Database Tool Designers http://msdn.microsoft.com/en-us/library/ms190415.aspx 2012 07 January2013

Last updated: 07 January 2013 16h50

SQL Server Database Coding Standard

Introduction

Note:  This standard is still in the process of being written: <Under Construction>.  Click here, for the older version.

To find a comprehensive guide on SQL Server Database Coding Standards, is not easy.  Many contributions are scattered across the internet, and most companies collate them into a proprietary held manifest, to which we have no access.

The purpose of a database coding standard would be to help database, and application developers, to firstly conform their code-style, and code-practices, and secondly create a maintainable solution.  It would even be a good thing to see people adopt a reasonably uniform style, on an international basis.  When browsing the usual sites, won’t it be grand to see database professionals coding SQL universally conformal.

When reading the book, Professional SQL Server 2008 Internals and Troubleshooting (Christian Bolton, Justin Langford, Brent Ozar, James Rowland-Jones, Steven Wort, and Jonathan Kehayias), I was pleasantly surprised at the SQL code-style.  Why, because it looks like a style I prefer.  The book is not consistent throughout, probably because of the different authors, so let’s get into the detail of SQL formatting.

In the SQL code-example image (SQL Code-style Sample), the first code block,  is from p47, fig. 2-16 of the book.  This is a beautiful layout.  Take note of the capitalised key-words, the indent between them, and the actual T-SQL code, as well as the closing of the statement with a semi-colon.  The only things I would like to change are:

SQL Code-style Sample

SQL Code-style Sample

  • A standard intent, between key-word (SELECT) and the T-SQL code, of three tabs.  This is to anticipate JOINs, which could be comprised of three words: LEFT OUTER JOIN.  The three tabs, allow for a seamless fit.
  • Moving the commas to the front, i.e. those separating columns in the SELECT statement.  This is a personal preference, because each comma can be aligned that way; whereas, if it is placed after the line they align according to the line’s length, and is more often than not, ragged.

The last example (in the image insert), often found as you browse the internet, is the most loathsome form of SQL, in my opinion.  It makes me cringe.  However, despite my personal quirks, it does not look too abominable.  As seen, it has structure, and it is very readable.  But, as we progress with this coding standard, it will become very evident that the longer, and more complex the code becomes, the more crucial a good choice of layout is.

Of course, style is an aspect of a database coding standard, there are a few other things that should also be considered.

This article is based on Microsoft SQL Server, and Transact-SQL, but that is of little importance, as most of the concepts can be equally applied to other database technologies.  Where proprietary language constructs differ, the principals governing style,  layout and capitalisation, are encompassing.

A standard should address at least, the following things:

  • Naming Standards
    • Database Objects
    • Databases,  Files, and File Groups
    • Project specific naming variations
  • Code
    • Formatting, and capitalisation
    • Aliasing
    • Variable declarations, and initialisations
    • Object comment decorations
    • Transact-SQL
    • Error handling
      • Standard
      • Custom
      • Project, or Enterprise specific
    • C# CLR
  • Enterprise best-practices, for database developers
    • Enterprise database development templates (boiler-plate code)
    • Files, and File Groups
    • Storage architectures, and implementation guide-lines
    • Data types
    • Dynamic SQL
    • Performance
      • Transaction Isolation
      • Execution Plans, Statistics IO, and Time
      • Query Hints
      • Indices
      • Referential Integrity
      • Temporary Tables
  • Visual Studio Database Projects
    • Configuring, and Managing a Database Project
    • Developing with Visual Studio, and Database Tools
  • Microsoft SQL Management Studio
  • Physical Data Modelling

This standard, being a coding standard, won’t elaborate on hardware.  Despite, dealing with files,  and file groups, strictly speaking also falls onto the configuration domain, do however exercise a direct influence on the code.  When creating tables, and indices, their locations have to be specified, and once specified remains under source control.  Therefore, if a file group is changed, code has to be checked out, and changed.

Document Conventions

Icons

 Hints and Tips Where any hints and tips are provides, this image is displayed.  A hint, or tip is not regarded as a standard, but as a consideration, augmenting, or empowering the standard.
 Mandatory Mandatory elements, are denoted with this sign.  These are the standard, and must be honoured in the enterprise.
Nota Bene Take note of a certain principal, or idea.
 Do Not Do not do this!
 Whatever Use it, don’t use it, make up your mind about it, whatever.
 Horse Dung That’s pure horse!

Terminology

Term Meaning
 Must, or Shall  This is a mandatory indication that the specified action must be performed.  There is no optionality, or variableness intended with this proclamation.
 May, or Can  An optional element is expressed, to be considered in light of its context, and decided upon by its estimation of quality.
 Should  Indicative of strong indication of use for purpose supposed, but not obliged.  For all purpose, and consideration, this should be used, and it is by qualification the right thing, however, it is not be enforced through the commands of mus,t or shall, and is therefore recommend, but not mandatory.

Naming Standards

Through Standardisation a few qualities are achievable, e.g. legibility, maintainability, transportability, and longevity .  There are few things so frustrating than inconsistency.  Inconsistent naming conventions create heaps of problems, not only to the human eye, but to applications, systems, and reporting tools.  If you ever worked on a large project, made up of several parallel streams of implementation, with common databases, you’ll find development often meanders their own path.  This leas to general confusion, and the road of pursuit ends in a waste of time, and money, producing a solution that is very cumbersome to maintain.
Naming conventions may overlap with other IT functions.  It could put control in various hands, which may be physically different departments.  Different naming conventions can cause overall inconsistencies.  This standard must be in conformance to those respective entities, from the point of view that general enterprise consensus must have been sought.  Creating any silo-based standard, process flow, or policy, is counter productive.

Hints and Tips
  • Any naming standard, is better than no standard
  • There isn’t a one-and-only globally-correct standard
  • A standard is only as good, as its objectives, and whether or not it is being used
  • Use the standard, if it has been put in place, and do update it where out of practice

General Considerations

Hints and Tips Favour readability over brevity.Choose natural, and intuitive names.Create names that catch the eye, e.g. use camel-case (pascal-case) to create visual hooks.  This notation may negate the use of the under-score, because it provides a significant visual differentiation in text.Consistency is more important than rule, but consider detrimental conventions, discussed in the “do not” indications.Using prefixes in object names, can help greatly with the organisation of objects, as they are displayed, not only in a database management user-interface, but also in source control, i.e. in a database project.When using a prefix, it must be used in the context of describing the object, in relation to its business taxonomy, e.g. CBS_ (Cbs) for Client Billing System, or CRM_ (Crm) for Customer Relationship Manager.Consider the use of Schemas, when considering a functional prefix.  The two concepts might clash, for the name, e.g.

  • SELECT CustomerID FROM [Cbs].[Customers]
  • SELECT CustomerID FROM [Cbs].[CbsCustomers], OR [Cbs].[CBS_Customers]
  • SELECT CustomerID FROM [dbo].[CbsCustomers], OR [dbo].[CBS_Customers]
Do Not
  • Avoid abbreviations, as the main name of an object, e.g. use Invoice instead of Inv.
  • Don’t write in UPPER CASE, its archaic, and very anoying.Never use sp_ (for a stored procedure’s prefix), and never tbl_ (for a table’s prefix), and never col_, Pk_, Fk_, for a column’s name. See nota bene for the two variations, when using prefixes in object names, otherwise never prefix an object name, because it is either stating the obvious, or may impact performance, such as the sp_ prefix resulting lookup, for strored procedures.
  • Avoid spaces, and special characters (with the provision on the under-score) in the names, even if the database allows it.
  • Don’t include table names in the names of table attributes, where the relationhip is obvious.
  • Don’t use any identifiers/ words that conflict with other programming languages.
  • Don’t use language-specific keywords, for names, e.g. GetDecimal, rather GetLength [6.].
Nota Bene  There are variations, on the usage of a prefix, in the name of a database object.  A couple of examples are:

  • a user-defined function, and
  • a view.

It is beneficial to prefix these with udf_, and vw_ (view), respectively.  It makes it clear what is being joined to, in a SELECT statement, which is to differentiate it from a table.  For all other object, don’t.

Mandatory Standardised naming for database objects, must be applied universally throughout a project, and the enterprise.  Consistency is more important than the choice.
Whatever  Name prefixes, may either be a three-digit capitalised acronym, followed by an under-score, or a three-digit camel-case acronym with no under-score.  The format depends on the organisation’s subjective preference.  Whatever is decided, consistency is more important than the choice.  Apply the same convention throughout the project, or better, the organisation.


In the table below, is a list of must use, naming standards, for database implementations for the organisation.

Naming Standards by Type

Database Name

This is the name given to a database, i.e. the one displayed by Microsoft SQL Server Management Studio (SSMS), under [Databases].Use camel-case to format the name.  It is important, to be as descriptive about the name, describing the functionality of the system, or business function, for which the database is being implemented.

Do Not
  • Do not use an acronym, as database name, even if the system is known by its acronym.
  • Do not use numbers, e.g. ClientBilling1 & ClientBilling2.
  • Do not make the name too long, restrict to about thirty characters.Do not start names with under-scores.
  • Never use a space in the name, even if the system allows it.
  • Do not use abbreviations in the name, e.g. CustRelManagement, for CustomerRelashionsipManagement.

Write out the functional description of the system, or company (depending on the size of the implementation) as succinctly as possible.

Examples:

The company name is Acme Corporation, and it only uses one database:

AcmeCorporation

AdventureWorks (Microsoft’s sample database)

The company has a huge database implementation, comprising several transactional, data warehouse, virtual databases, and some data-marts:

ReferenceData

EquityTrading

DerivativeTrading

ClietBilling

CustomerRelationshipManagement

Intranet

DataAlignment

AcmeWarehouse

AcmeSalesMart

AcmePurchasingMart

Hints and Tips
  • When naming a SQL Server instance, take note that the instance has the server’s name, as the first part of the full name, e.g. <server name><instance name>.
  • The server name would be a name defined by the Infrastructure department, in accordance with their server naming conventions. As database administrator, or architect, you may not have any influence over that.  It may also be the case for the instance name, and it could be something as non-descriptive (to you) as: SQL02.The fully qualified name for a database is:
    • <server>.[instance].<databasename>.
  • A Database [Instance] is optional, so when reading the name, it should make sense about the database.
Mandatory
  •  View the database name, as a function of the fully qualified name, e.g. <server>.[instance].<databasename>.  Name the instance, as a function of:
    • The application being serviced
    • The domain of the instance, viz. Production, User Acceptance Testing, Testing, or Development
  • For example: D4DBSL0121SupplyChainProd.  Purchasing, where SupplyChainProd denotes the application, and the domain or environment.
  • When specifying a linked-server name, use the instance name, or if the server has no instance, create the linked server’s name, in accordance with the instance’s criteria.

Database File Group Names, and Database File Names

A database File Group, is a logical name, as container, for database files.The default File Group name is: PRIMARYDatabase files are comprised of [3.]:

  • Primary
  • Secondary and,
  • Log Files
Database Files And File Groups

Database Files And File Groups

A database File Group, is a development entity, i.e. is is put under source control, as part of the database object’s schema definition.  For example, when a table is defined, it’s FILE GROUP is specified as the logical target with which the table’s creation is associated.Provide a meaningful name, denoting the kind of object, and/ or the business designation of the object.For example, grouping tables by function, or Input/ Output characteristics, e.g. Trades, and Orders, split between them, into  [TRADES] and [ORDERS] file groups.  Data, inserted into the respective tables, are stored in data files, according to the FILE GROUPs.

File Group Name Examples:

  • PRIMARY,
  • TRADES,
  • ORDERS,
  • BILLING,
  • TRADESINDICES,
  • ORDERSINDICES

Data File Name Examples:

  • PublicEquityTrades001.ndf
  • EquityMarketOrders001.ndf
Complete Horse There is no truth in creating multiple log files, to increase performance, the file is sequentially written to, and provides no advantage in having multiples.  Create only one. [4.]
Hints and Tips Use a numbering system, to separate multiple user-defined data files, for the same DATA GROUP.  By virtue of being a data-file, the database designer might not have control over the naming convention, but only over the FILE GROUP.

Table

A table’s name should be viewed as a construct between the owner/ role, and the actual name: [<role>].[<table name>], e.g.

  • [Cbs].[CustomerInvoices], or
  • [dbo].[CbsCustomerInvoices], or
  • [dbo].[CBS_CustomerInvoices]

Where tables are referenced by systems, but do not belong to a particular system, use n system-agnostic prefix, e.g:

  • [RDA].[Customer], or
  • [dbo].[RDA_Customer], or
  • [dbo].[RdaCustomer], or
  • [dbo].[ADM_Customer], or
  • [dbo].[AdmCustomer]

Note: RDA – Reference Data, or ADM – Administrative, i.e. it’s not system specific, but common to a couple, or few systems.

Kinds of database tables are:

  • Normal tables – containing data for a specific entity
    • Business Data – Business objects, e.g. Orders, Customers, Invoices.
    • Application Data – User interface object data, e.g. drop-down list specific
  • Join/ configuration tables – contain configuration data, e.g. Customers joined toOrders
  • Temporary tables – temporary calculation staging results
    • Session scope – visible to the connected SPID (server process identity) that created it
    • Global scope – visible all SPIDs, using it, inclusive of the creator, until all SPIDs disconnect
    • Variable tables

The naming convention should be similar, for each of the table types.

Mandatory
  • Create table-names in the plural, e.g. Customers, and not Customer, or Personnel, or Employees.Configuration (junction) tables must be named:
    • <Primary table name> And <Secondary table name><Configuration>
    • Example: CustomersAndOrdersConfiguration
  • Refer to the ISO/IEC 11179 standard [7.].
Whatever
  • Use a prefix, for grouping tables according to the business system in which they are used.
    • Example: Reference Data can be prefixed with RDA_ (Rda), or ADM_ (Adm), the latter meaning Administration.  Reference data may not belong to a particular business system.  For example, Customer Billing might use Customers, while Business Surveillance might use Billing, as well as Customer tables.
  • For tables that belong to a user-interface (application screen) only, a prefix may be used, to group them separately from business specific tables, where these are defined in the same database, as the business objects.
Do Not
  • Do not prefix a table name with a superfluous acronym like “tbl_”, it just serves to make you look stupid.
  • Don’t use any classification acronym, or word, to differentiate variable temporary, and global temporary tables.  They have their language-specific classification already, e.g. @ (variable), # (temporary), and (##) global temporary tables.

View

A view is noting other than a virtual table, or a definition (query) for data to be materialised, at run-time, from defined tables, according to the view’s defined schema.  The naming convention for a view is the same, as for a table, with added specialisations:

  • A view is a specialisation of a table, but different to a table.  Because of the similarity in which they are defined in a SQL query, it might be required that the database developer is aware of this.  Therefore, the naming of the view, must be different, so that it is apparent that it is a view:
    • Add a prefix (Vw, or View) to the view’s name.
  • Views can denote a more complex result than its base (source) tables.  The view might compound the query logic, by combining base results, even aggregates, in a materialised view, at run-time.  Therefore, the naming convention must accommodate the view’s function, as much as possible.
    • [Billing].[ViewCustomerInvoiceAggregatePerQuarter]
    • [dbo].[VwSalesAnnualCustomerSalesSummary]
    • [dbo].[Vw_Sales_AnnualCustomerSalesSummary]
  • The naming of views, may contribute to ease of development, and trouble resolution, because the object (from where data is requested) is readily identifiable as a view, and would not be mistaken for a table.
  • Views can be used as security principals, to provide users access to the materialised results, even where they might not have access to tables queried by the view.
Mandatory Use the prefix Vw, or View, to denote the object as a view, in order to differentiate it from normal tables, and user-defined functions, all of which are selected from, or joined on, in a standard SQL query.
 Whatever  Views can be utilised as reporting entities, or as specific data queries.  You could consider customising the naming, to reflect this.

  • Reporting: [dbo].[VwSalesAnnualCustomerSalesSummary]
  • Specific Data: [dbo].[VwInvoicesCustomersAndOrders]

Table Attributes

  • Columns
  • Keys
  • Constraints
  • Triggers
  • Indices
  • Statistics

Table attributes are part of a table’s schema definition.  Because the table is the super structure, it is obvious that the attributes belong, or are in association with the table.  Therefore, the table’s name does not have to be repeated in the naming convention of the attribute.

Columns:

Columns describe the properties of the table.  The column’s name must describe the purpose, and value of the column, as succinctly and naturally as possible:

  • Columns with identity fields, must be so indicated, e.g. EmployeeId, or InvoiceNumber.  These columns must be of Integer or BigInteger data-types
  • Columns with code identities, must be so indicated, e.g. ProductCode, or InvoiceNumber.  These columns must be of Varchar, or NVarchar data types
  • Columns with descriptions, must be so indicated, e.g. ProductDescription.  These columns must be of Varchar, or NVarchar data types
  • Columns with boolean types, must be so indicates, e.g. IsActive, HasAccess, IsValid.

Note: The suffix of Number (as an identity) could either denote an integer or string value, but where a code is used, it is an alpha-numeric (string) type value.

Keys:

A table’s primary key, must be prefixed with “PK_”, and indicate if it is clustered or non-clustered.  In Visual Studio 2012, the primary key should not be created separately, i.e. in a Keys folder.  If this is done, the functionality of Visual Studio is short-changed, where the primary key can be defined, using the graphic table designer screen, by simply clicking the field as a primary key.  Note: Do inspect the name given, as this standard prescribes a different convention.

A table’s foreign key, must have the same name as the column in the primary-key table, preceded by the name of the primary table.

Keys must be defined, respectively, as follows:

  • “PK_CIX” Primary Key, clustered index (uniqueness is inferred): PK_CIX_CustomerID
  • “PK_NCIX” Primary Key, non-clustered index (uniqueness is inferred): PK_NCIX_CustomerCode
  • “FK_” Foreign Key:
    • FK_<primary table name>.<primary key>_<foreign key column name>: FK_Customer_PK_CustomerID_InvoiceID

Constraints:

Table constraints are part of the table.

Default and Check Constraints

  • “CK_” Check constraint, e.g. on date range: CK_DateRange
  • “DF_” Default constraint, e.g. on ProcessingDate: DF_ProcessingDate

Triggers:

Triggers are like stored procedures, but attached to a table, and acts in response to a table action, viz. Insert, Delete, or Update, in an event-driven fashion, invoked by SQL Server.

The trigger name should be natural, and descriptive.  It belongs to a table, so it is not necessary to mention the table, again, in the name.

Generic Name:

  • <prefix (t|Trg|trg|Trigger|trigger)>[_]<Trigger Type (After|InsteadOf)><Action (Insert|Update|Delete)>

Name Examples:

  • tInsteadOfDelete
  • TrgAfterUpdate
  • trgAfterDelete
  • triggerInsteadOfInsert

Indices (Indexes):

Indices are created as the table, for clustered indices, and off-tables, as non-clustered indices.

Clustered, Clustered Unique, Non-clustered, and Non-clustered non-unique.

A table can only have one clustered index, because it is the table, and multiple non-clustered indices, because they are created off-table.  A clustered index can be the primary Key, but it does not have to be.  A primary key should only exist, when the table has referential integrity.  A primary key ensures uniqueness, and non-null-ability.  Both clustered and non-clustered indices can be non-unique.  However, a clustered index, as primary key, cannot be.

A primary key that is a clustered index, takes the naming convention of the primary key, described next, under keys.

  • “NCIX_U_” Unique, non-clustered index: NCIX_U_MemberIndustryCode
  • “NCIX_NU_” Non-Unique, non-clustered index: NCIX_NU_MemberIndustryCode
  • “CIX_U” Clustered index, unique: CIX_U_CustomerId

Statistics:

SQL Server, when auto generate statistics, is turned on, automatically creates table statistics, by providing a system name, e.g. _WA_Sys_00003_3CF40B7E [8.].

When creating a user-defined table column statistic, any (free-text) name can be given.  The statistic is bound to a table’s column, and listed under [Statistics].  It is beneficial to know on which column it is created, the table is immaterial, because it is obvious.

Generic name: <prefix (ust|ustat)>[_]<Column Name>

Name example:

  • ustCustomerRoleId
  • ust_CustomerRoleId
  • ustatCustomerRoleId
Mandatory Do prefix table constraint-names, with the appropriate prefixDo prefix keys (primary & foreign), with the appropriate prefixDo prefix indices, with the appropriate prefix, and specify the uniwue/ non-unique indicator.
Whatever  A column may have the table’s name, in its name, e.g. CustomerId, as opposed to Id.  When using a table, and its columns in a query, the table name must be aliased, and also, consequently the column.  This should provide a unique reference, and a designation of which table the column belongs, negating the necessity of having the table’s name in the column name.  This, however, depends on how well the SQL query is written, i.e. how attentively this standard is being followed.
Do Not
  • Do not prefix a table’s column name with: COL_, or col_, or cl, or anything to denote that it is a column.
  • Any table attribute that does not reference another table, must not have the table’s name, as part of its name.
  • Do not name a column, by specifying “Id” in the name, where it is not a numeric data type.
  • Similarly, do not specify “code” in the column’s name, if it is not of a string type.Do not name a boolean column without a boolean descriptor, e.g. Is, Has.
Horse Dung
  • A clustered index, does not have to be the Primary Key.  A non-clustered index, can be the primary key, given the index is unique, and not-null.
  • A primary key does not have to be the auto-incremented integer column of a table.  However, a primary key must be unique [5.].

User-defined Functions

  • Table
  • Scalar
  • Aggregate

User-defined functions are used in similar fashion to tables, and views when joined to, or selected from, in SQL queries.  For this reason, their names should be considered akin to these other objects.A user-defined function also shares characteristics with stored procedures, especially because they are able to return a scalar-value.   It also has a parameter list, or input value-list, such as stored procedures, and unlike tables, and views.Another goal to strive towards, is finding a user-defined function, if a database has many of them.  To achieve this, one should add some attribute.Furthermore, a function has many functions.  It can be used to selectBecause of these similarities, and especially on the bearing towards views, and tables, the naming convention of a user-defined function should reflect uniqueness.

To avoid going on about: “we are all related”, let’s set a standard.

Prefix:Do prefix the name of a user-defined function with:

  • ft_ Tablular function
  • fs_ Scalar function
  • fa_ Aggregate function

Application (Business Specialisation) and Sub-application:

The function’s name, must be able to indicate meaning, within the context of the query, so that developers are able to easily identify them accordingly.  The function’s name must also be locatible where referenced in the database management, or the development application.  For this purpose, an Application, and Sub-application identifier are used.

Process:

This is the functionality or processing, performed by the user-defined function.  It denotes the name of the function.

Generic name:

  • <prefix>[<Business Specialisation>][_][<Business Sub-specialisation>]<Process>

Name examples:

  • ftCustomerAndCustomerRoles(), or
  • ft_CBL_CustomerAndCustomerRoles() [where CBL is the business specialisation], or
  • ft_CBL_Invoicing_CustomerStatements() [where Invoicing is the sib-business specialisation]

NOTE:   The usage of the under-score [_] should be gauged, to see that it makes legible sense.

Parameters:

Disambiguation of parameters, alleviates many a development woe.  Distinguish parameters from locally defined variables.

Name: The name of a parameter is the same type of name for any variable.  See later section on variable names.

Prefix: A prefix of “p”, e.g. pBillingRunDate, is sufficient to describe a user-defind function’s parameter.

Generic name: <prefix (p) [p-input parameter])<Parameter Name>

Mandatory Do prefix the user-defind function, so as to differentiate its imlementation with that of views and tables.User-defined function parameters must be prefixed, simply for disambiguation.
 Do Not Do not add a verb, as action descriptor, to the function’s name, e.g. dbo.ftGetCustomerAndCustomerRoles, or ftSelectCustomerBillingInformation.  The reason being, that any development environment, or editor, sorts alphabetically, and will consequently group all the Get’s, and all the Select’s together.  This is counter-intuitive to any human being, looking for objects by business specialisation.  A function is a selection mechanism, so one is always to expect something to be returned, and not that the database is maintained.

Stored Procedure, and Stored Procedure Parameters

A stored procedure is a container for storing executible code in a database.  The code can execute, very much like that of a view, function, or trigger.  However, there is a distinct difference, in that a stored procedures can not be used in a SQL statement for INSERT, UPDATE, DELETE, or SELECT.  The keyword EXECUTE is alway associated with the execution of a stored procedure.  This modus of execution, makes the stored procedure unique.  Therefore, it does not have to be identified in a specific manner (such as adding a prefix), because it can’t be confused.

A stored procedure is able to return results in four ways, viz. by result-set (table), scalar-value (numeric), return value (simplistic boolean or integer) value, or output parameter(s).

Application (Business Specialisation) and Sub-application:

The stored procedure’s name, must be locatible, where referenced in a database management, or development application.  For this purpose, an Application, and Sub-application identifier are used.

Action:

Because a stored procedure, is a multi-purpose functional database code container, it not only returns data, but has the ability to insert, update and delete data from a store.  For that reason, the name of the stored procedure has to be disambiguated.  To this end, an Action descriptor, is supplied.

Generic name:

[<Business Specialisation>][_][<Business Sub-specialisation>][_][<Action>]<Process>

Name examples:

  • CBL_Invoicing_SelectCustomerBillingItems
  • CblInvoicingSelectCustomerBillingItems
  • SCM_Purchasing_UpdateSupplierOrders

Stored Procedure Parameters:

Disambiquation of parameters, alleviates many a development woe.  For example, within a large stored procedure, it is expedient to know which values are local variables, input, or output parameters.  It makes it much easier for a developer to identify values, and aids to faster development time.

Name: The name of a parameter is the same type of name for any variable.  See later section on variable names.

Prefix: A prefix of “p”, e.g. pBillingRunDate, is sufficient to describe a stored procedure’s input parameter.

Consequently, an output parameter prefix, should be: oNumberOfInvoicesInStatement.

Generic name: <prefix (p|o) [p-input parameter|o-output parameter])<Parameter Name>

A return value, is any functional local variable that is wrapped in the RETURN(<local variable:integer>) function.  The function denotes its type, i.e. return value, and the function parameter, the data type, i.e. integer.

Mandatory
  • Use a natural name that describes the function of the stored procedure as succinctly as possible.
  • Be consistent in the choosing of the stored procedure’s name, from the Generic name specification.
  • Disambiguate stored procedure parameters, by prefixing them.
  • Stored procedure parameters, must be prefixed, according to the type, and their names, specified by the rules of variables.
 Do Not
  • Do not prefix the stored procedure’s name with sp_, because it is reserved for system stored procedures, and may cause a future name clash.
    • Secondly, where a name clash is the case, SQL Server first executes the system stored procedure.
    • Thirdly, the server first looks in master, to see if it can find a system stored procedure (and if not), executes the user-defined one, given that a fully qualified referenced name is not used
  • Do not use another type of prefix, other than sp_, e.g. usp_ (user stored procedure)Do not use verbs in the name, aimed at describing the action, e.g. Select, or Get.  It causes object sorting in development and administration environments to sort counter-intuitively.
 Whatever When considering using a Business Specialisation, and Business Sub-specialisation, especially in connection with Action, consider the sorting order of the names of stored procedures.  Omitting any of these, or using a combination of some, might cause bizare sorting arrangements.

Variables, and Parameters

Any database code object, e.g. user-defined function, or stored procedure, can take parameters, and can have local variables.  For ease of identification, in vain with the entire purpose of naming conventions, these also fall part of the same regimen.Local Variables:

Object Parameters:

Objects, viz. stored procedures, and user-defined functions, have parameters.  They are specialised in that a stored procedure has both input, and output parameters, while a function only takes input parameters.  The naming convention follows prescriptions for each object, and generally according to local variables.

But, as with many things, there are variations, and it depends on the variable’s scope in application.  On large projects, the coordination between database objects, and applications, can be performed directly, via a Data Virtualisation stratagem, e.g. Object Relational Mapping (ORM) solutions.  Keeping track of which variable is what, and what data type conversion to do, can become tedious.

To resolve such predicament, the variable can be decorated, so that it might be identified for more than one scenario.

Generic name:

Stored Procedure:

<prefix (p|o) [p-input parameter|o-output parameter])<data-type acronym><Parameter Name>

User Defined Function:

<prefix (p) [(p-input parameter])<data-type acronym><Parameter Name>

Local Variables:

These are named as closely to what they are, e.g. EmployeeIdentificationNumber, as logic allows.

Generic name: <@v><Variable Name>

NOTE:   It is possible to have variables that are used like constants.  For these, replace the <@v>, with <@c>, to denote the difference.

Mandatory Prefix variables and parameters.
 Whatever For large projects, include a datatype descriptor in the parameter’s name, to make it easier for developers to correlate database and application parameters.

Suggested SQL-Data-Type-Prefix Acronyms, for Parameters

Using acronyms, described below, as prefixes for SQL object parameters, they can be readily identified on the application side.

Name examples:

  • @pIntbInvoiceNumber
  • @pXmlTradeCaptureReport
  • @oGuidsOrderMessageId

 SQL Data Type

Prefix

 BigInt  intb
 Int  int
 SmallInt  ints
 TinyInt  intt
 Numeric  num
 Bit  bit
 Decimal  dec
 Money  mon
 SmallMoney  mons
 Float  flt
 Real  real
 Date  d
 DateTimeOffset  dtoff
 DateTime2  dt2
 SmallDateTime  dts
 DateTime  dt
 Time  t
 TimeStamp  ts
 Char  str
 Varchar  str
 NChar  stru
 NVarchar  stru
 Text  txt
 NText  txtu
 Binary  bin
 VarBinary  binv
 Image  blob
 Cursor  crsr
 HirarchyId  hid
 UniqueIdentifier  guid
 SequentialUniqueIdentifier  guids
 SQLVariant  varsql
 XML  xml

Development Conventions

SQL Server development comprises all T-SQL (transact SQL), and C# Common Language Runtime (CLR) development.

Code Formatting

In code, formatting is paramount to a legible, and maintainable code base.  Some formatting aspects are subjective, and organisations, even persons, may differ diametrically.  This standard is one way of standardising database development code formatting.

A development template (boiler-plate) is a very good mechanism through which to provide developer guidance.  The following description of standardisation, is combined, and delivered in a template.

Formatting a  Basic SQL Statement

The basic SQL statement serves to illustrate keyword capitalisation, and statement formatting.

Basic SQL Statement Formatting

Basic SQL Statement Formatting

The basics is to format the statement, with future additions in mind.The placement of the comma-separators, for table columns, is subjective.  Many put the comma after the column name, but that causes a ragged placement, which might not produce the most pro-CDO outcome.

Getting the basic statement correctly formatted, helps with more complicated SQL.

 Mandatory
  • Capitalise keywords.
  • Use a 3-tab indent, between SELECT and the first column name, which is also applicable for the spacing between FROM and the table name.  This accommodates later usage of LEFT OUTER JOIN keywords.
  • Use a fully qualified name (three part name), as reference to the table name, from which to select.Use block-brackets, for words, same as keywords, or where they contain spaces.
 Whatever Use block-brackets around column names, and table references.  This is a subjective coding style, unless the word being .

Formatting a more Complex SQL Statement

A complex SQL statement includes JOINs, nested statements, aliasing, or is even a Common Table Expression.

Complex SQL Formatting

The SQL statement depicts a more complex query, one with a Common Table Expression (CTE), and a JOIN.  When looking at SQL code, it must be pleasant.  Uniformity, without obsessive compulsiveness.

Aligning the code, by keyword, and statement nesting-scope, causes a pleasant uniformity.  The alignment of the aliases, can be according the nesting, but it looks nicer, just like the preceding comma placement that avoids a ragged appearance.

Note: The code is a database performance query, written by Glenn Berry (sorry–formatted by me).

The example does not use a LEFT OUTER JOIN, which would have indicated the requirement for a three-tab indentation, between SELECT and the column name, or FROM and the table reference.

Mandatory
  • Use tabs, or spaces, to offset and format code lines, by keeping lines in the same columnar alignment, according to the scope of the nesting.Place all alias definitions inside square (block) brackets and specify the AS keyword, to denote them.
  • Where referencing a column, by alias, ensure that it uses a bracketed instance of the reference.  This significantly increases readability, and disambiguates the column-to-table relationships.
  • Be as pedantic as feasible, by ending statements with semi-colons.
  • Take note, that a statement preceding a CTE, must be terminated by a semi-colon, otherwise the CTE throws the error: “Incorrect syntax near the keyword ‘with’“.
  • Make aliases descriptive, yet short.  There’s nothing as silly as having an alias [X], or [Y].  When the SQL statement is long, one could easily lose the context of the referenced column, because x, and y don’t mean much.
 Do Not  Do not use a column number, when specifying the ORDER BY predicate.

Stored Procedure Formatting

A stored procedure is a typical code container, able to serve as demonstration of this standards, for all other code containers, e.g. user-defined functions, triggers, or SQL scripts.

The format of a stored procedure’s create script, is comprised of:

  • Create statement
    • Procedure Name
    • Input, and Output Parameters
    • Execution (security) Context
  • Flower Box
    • Abstract, describing the function of the procedure
    • Author details
    • Version details
  • Declarations, Initialisations & Validations
    • Setting of Directives and Transaction Isolation Levels
    • Local Variables, and their initialisations
    • Any validations on parameters
  • Main Code Execution
    • Transaction
    • SQL Query
    • Return Value
  • Error Handling
    • Catch
    • Custom Logging
    • Return value
  • Clean-up, or Housekeeping
    •  Transaction Isolation Levels
    • Directives
  • Additional Information Box
    • Edit history
    • Any other pertinent information
  • Extended Properties
    • Author
    • Functional Description
    • Version
    • Current Editor
    • Edit Date
    • Template Version

The Stored Procedure CREATE Statement

Stored Procedure Create Statement
The CREATE statement comprises the procedure’s name, parameters, and an EXECUTE AS specification.The WITH EXECUTE AS statement provides the stored procedure with a user context to use, for validating permissions on objects that are referenced by the module.

The parameters, differentiated between input and output, are prefixed accordingly.

The Stored Procedure Flower Box

Stored Procedure Flower Box

A flower box is probably a spill-over from main-frame programmers.  SQL coding, with the exception of SQL CLR, is very main-frame like.  It has the same top-down layout as Adabas, and Cobol programs.However that sides, I like it.

One could argue that developer interfaces, such as Visual Studio, with Team Foundation Server (TFS), keeps more than adequate track of versions and authors, and that by specifying attributes, duplicate work is being undertaken.  That may be so, but more often than not, branch information in TFS gets turfed, objects dropped from the database, and there goes the meta data history.  It is, unfortunately, dependent on being maintained by the developer, but with a firm development life-cycle practice, good process and management, and above all, the adherence to a standard such as this one, it shouldn’t be a problem.

An aspect that seems helpful, is to maintain an example of the object’s execution.  More often than not, the database on which it is deployed, still has valid data, for such a test-type example to execute and return meaningful data.  It helps, with later maintenance.  Also, it might be a while since a developer has used output values, or a returned value, and such an example lends itself to a speedy latch.

Mention of the Coding Standard, used when last dealing with this object, might also be a much use, especially to the current editor.

People come and go, so the name of a developer, especially where contractors were used, may not be important.  However, if that person is still available, given memory server him well, some guidance may still be sought from such.

The Stored Procedure Declaration, Initialisation, and Validation

Stored Procedure Declaration Initialisation and Validation
The Declaration, Initialisation, and Validation section, allows for the setting of directives, transactional isolation, local variables, and (if required) validation on input parameters.

The SET NOCOUNT ON, if this is not familiar yet, suppresses row count information from being returned to a calling application, as well as, depending on whether it’s specified before @@ROWCOUNT, resets its value, as any statement would.

Transaction isolation is set in accordance with the specific requirement of this stored procedure.

The XACT_ABORT, is a SQL 2005 optimisation that forces a roll-back and termination of the entire transaction (error severity level 11-16), on error.  If it is left off, only the transaction, causing the error, is rolled back, i.e. SQL chooses how to resolve error.  It’s used in combination with TRY. . . CATCH, the latter to handle the error and the XACT_ABORT to determine what to do if an error happens.  It would appear that using XACT_ABORT, by itself, with no TRY. . . CATCH, is faster [9.].

Standard error variables, and specific query variables are declared separately.  Their initialisation, where applicable, can be done in the same statement, as the declaration.  Note the variable prefixes.Alignment is important.

See the variable declarations, aligning not only the names, but also the data types.Take note of the headings.  See the later section on textual (comment) decorations.

Mandatory
  • Do set the directive NOCOUNT to ON.
  • Do the basic alignment, using either tabs, or spaces.
  • Prefix local variables.  Use @v – as local variable indicator.
 Do Not
  • Do not forget to SET NOCOUNT ON;
  • Do not cause any ragged-edge alignments.
 Whatever
  • Consider the transaction isolation level.  By not specifying it, the default of READ COMMITTED, is assumed.
  • Initialise variables, as part of the declaration, where it makes sense.

Main Code Execution

For a stored procedure, the main code execution section, is the guts of the object’s functionality, and the purpose for which it had been written.  As mentioned above, transactional handling can be wrapped in a TRY. . . CATCH with XACT_ABORT ON, or just run with XACT_ABORT ON.  However, the stored procedure is the object of choice, for error handling, and custom logging, where implemented.

Stored Procedure Main Code Execution

The example, indicates that the executive SQL code, is wrapped in a TRY. . . CATCH.  Notice also, the RETURN, in this example, sending back a specific integer values, one that has meaning to the context for which it is returned.  If the procedure does not throw an error, the return value is something meaningful, in context of the execution [10.], but not a business relevant figure, and not NULL.

Wrapping the SQL statement in TRANSACTION depends on the nested level of the stored procedure, or how the transactional management is being implemented.  But, if it’s handled in this stored procedure, it must be wrapped.  With SNAPSHOT isolation, even a pure SELECT statement must be wrapped [11.].

Mandatory
  • Do demarcate this section with an appropriate banner, i.e. flower-box textual comment.
  • Do the basic alignment, using either tabs, or spaces, see the formatting of SQL statements earlier in this standard.
  • Use TRY. . . CATCH, for error handling, especially for custom logging.
 Whatever
  • Utilise return values, where applications can benefit from it.

Error Handling (Catch)

The CATCH, or error handler, is an important section of a stored procedure, if you would like to know why it went boom!

It can get very complicated, depending on the level, and finesse of the handling.  The XACT_STATE (ms-help link provided) can be inspected to determine the state of the transaction.  Depending on the nesting-level, i.e. the sequence level of stored procedure call, the error might be handled differently.  SQL Server returns the error tree, one for each stored procedure, when it fails, to the first stored procedure in the call-stack.

Stored Procedure Try_Catch

The RAISERROR, where the procedure failed to commit the transaction, bubbles-up to the calling procedure.  This is also the place, in the code, where a custom error handler can be called.  It might be expedient to log stored procedure errors, by sending the relevant details to a handler (other stored procedure) that writes the information to a database table, or central error repository.  If such events are logged to the system’s event log, enterprise exception applications, such as System Centre Operations Manager, can retrieve the log and report it to operational staff, in the company, for resolution.

This example provides a guide-line, but the specific implementation will depend on the available error logging abilities of a company.  In this case, a descriptive error message is generated, indicating the error line, procedure, error number, severity and state, and sent to the calling procedure.

Clean-up, or Housekeeping

Crossing the t’s, and dotting the i’s.

Stored Procedure Clean-up and Housekeeping

SQL Server will, when the query exits, resume its defaults, so strictly speaking, these actions are not necessary.

Additional Information Box

This “flower-box” decoration, is quite the same thing as described above, as the flower-box.  In this instance, it keeps information about the edit history of the object, and other pertinent information about the object.

Stored Procedure Additional Information Box

Again, one could argue that source code team systems keep an edit history, but still, these also lose the history.

Extended Properties

Extended properties, are user-defined values that become attributes of a stored procedure, and are referenced via Stored Procedure Properties, after it has been deployed to the database.

Stored Procedure Extended Properties

Why use them?  The argument is similar to using the flower-box for adding Additional Information to the code of the stored procedure.  It’s also a step towards meta-data, and a data dictionary, plus it’s also a documentation aid.  It can be very powerful where applications read these properties, in order to evaluate the object consistently, and treat the data in the same way [12.].  With Visual Studio 2012, or adding SQL Server Data Tools to an existing Visual Studio 2010 environment, extended properties are properly supported.  The extended property statement is appended to the end of the stored procedure create script, or as a file of the type “extendedproperty.sql” in the folder <objects> to which it is attributable.

User-Defined Functions

Functions have three types, viz. tabular, scalar, and aggregate.  The scalar and tabular functions can be applied in a variety of ways, e.g. in-line, or multi-statement functions, as part of a SELECT statement.  The aggregate functions are created through CLR integration.  With SQL Data Tools, or Visual Studio/ SQL Server 2012 development, CLR objects, and the assembly, has been made part of the build/ deploy.  It’s drop-dead-easy to work with database projects since this addition.

User Defined Functions in Management Studio

The standard is similar for SQL user-defined functions than for stored procedures.

SQL Code Commenting

Code comments are required for formatting, as well as functional, and code implementation clarifications.  So far, flower-box inclusions, as part of the code format, has been specified.  Other commenting styles are:

  • Banners
  • Single line code clarifications
  • Paragraph style introductions

SQL Code Comments

 Mandatory
  • Use banners, to separate distinct functional areas, including a succinct description of the section’s function.
  • Use a single line delineator where a section has to be headed, but there is no need of a verbose description
  • Ensure that spacing is provided, as indicated, to align comments, and beautify their visual appeal
  • Variations in commenting, such as using a banner with description, but the first prefixed by the double-dash, and the second with a slash-star, is not acceptable.  It must be used consistently, the one, or the other.
 Whatever It does not matter what style of commenting is used, as long as it is used consistently.

SQL Common Language Runtime (CLR) Integration Standards

When to use the CLR

The CLR, for SQL Server, has been around since SQL Server 2005.  To develop SQL Server Database projects, Visual Studio could be used, but unfortunately, it was not that easy.  Only after the release of SQL Data Tools [13.], and Visual Studio 2012, did it (in my opinion) become a feasible thing to make easy use of the CLR capability.  This, especially because it can now be deployed in one-click-style.  Before it was a very cumbersome process, outside of the database project, for most of the deployment, requiring quite a bit of manual labour.

The rule-of-thumb, for using CLR objects in a database project, is to perform operations that are too clumsy for SQL to do.  What are they [14.][17.]?

  • String manipulation – dynamic SQL constructions
  • Regular Expressions [15.]
  • Computation orientated queries, requiring the .net framework, e.g. the Black-Scholes option pricing model [16.]
  • SQL Process Controllers, with thread management, or iterations
Mandatory
  • Do use the CLR where the code to be executed is:
    • decision-rich,
    • non-set-based,
    • calculative,
    • has to utilise regular expressions, or
    • is a decision-rich construction of dynamic SQL
  • Do run batch-controllers, and data-intensive process controllers on the database, by coding them in the CLR.  Note: define what is meant by “batch controller”, and don’t implement an application that is better suited in a .net container.  See “whatever” below, for further clarity on this.
  • Do use CLR objects, e.g. stored procedure, for creating dynamic SQL that is dependent on elaborate business rules, comprising many input parameters.  The query-plan, resulting from the submission of a dynamic SQL call through sp_executesql, with parametrisation, might be a much more optimal plan, than including a myriad of input parameters, through standard TSQL.
  • Use SQL Data Tools (Visual Studio 2010/ 2012) projects to incorporate CLR database development.  The datadude version is way too cumbersome.  Note: In Visual Studio 2010 with SQL Data Tools, the project properties must be set to .net 3.5, it is not capable of .net 4.
  • Enable the clr function on the database server.
 
Do Not
Do not use CLR objects for manipulating set-based data sets, i.e. a function that should ideally be coded in traditional TSQL.Do not set a name space in the CLR class.
 Whatever
  • A business process controller, some code that schedules or brokers decisions about the execution of database objects, based on some business rules, can be coded in .net, to run out of a managed code container, such as a C# application of Windows service.  This is probably the best space to do it in, if it entails threading.
  • However, when that controller is a data processing function, it might just be that the closer to the data it executes, the better.  It also depends on exactly what is done by the controller.  One wouldn’t implement elaborate controller that could function in systems such as Control-M, or any other batch controllers.  It would be a menial object with a more than average number of IF. . . ELSE decisional statements, compounded by string manipulations and the likes.

CLR Database Interaction

Using CLR objects facilitates the CLR .net language run-time, in this case C#, to be available for writing the objects, and using the available framework functionality to implement them.  This is a jump up from the database, where SQL lives.  However, interaction between the CLR and database strata is not only possible, but would most probably occur.  This standard details the SqlFunction, and SlqProcedure variances.

CLR SqlFunctions and SqlStoredProcedures are defined, using attributes [20].  The Microsoft.SqlServer.Server namespace contains every possible attribute.  The first method in an object, is the object type, e.g. SqlFunction, but it can also be decorated by attributes, as directives or properties for the object built in the datbabase.

SqlProcedure

Blahblah

SqlFunction

A CLR user-defined function can be decorated with a few attributes [19].

  • IsDeterministic – Idempotent if true, i.e. returns same results when called with same parameters
  • DataAccess – DataAccessKind.None/ Read, if reading data from context SQL connection
  • SystemDataAccess – Reading system tables, SystemDataAccessKind.None/ Read
  • IsPrecise – Determines if to do floating point operations, true does not use FLOAT
  • FillRowMethodName – Method in CLR code, used to perform table-valued filling of data
  • TableDefinition – The table structure to be returned by the TVF
  • Name – Name of the SQL function, the one Published to the database
 Mandatory Use regular connection when connecting to a remote server [18] for data.Configure the CLR assembly for external data access [EXTERNAL_ACCESS] on the project properties page, if data-access, outside of the local server is required.  Note: The security context is SQL Server service account.
 Do Not Don’t pass table-valued-parameters to CLR functions, it can’t be done.Don’t use returned integers other than SqlInt32, or System.Int32.
 Whatever

CLR Code Formatting

CLR code, is essentially .net code.  In this standard’s case C#.  The same formatting rules, governing C# code, should be applicable in the database CLR.  There’s no need to step on the toes of an existing application coding standards.  It should be honoured in this standard.

 Mandatory
 Do Not
 Whatever

Glossary of Terms

Word, or Acronym

Meaning, and Description

 Database  A repository, in which data is stored, usually a relational database.  It is a logical grouping of data files, each stored on a disk location.
 Relational Database  This is a term, used to describe the popular notion of a database.  This is a structure in which data is stored, made up of objects, such as tables, and other programmable entities, such as stored procedures and functions.  The relational model was first defined by Edgar Codd of IBM in the 1970’s.
 Table  A table is an object of a database, in which data is stored in rows and columns.
 View  A view is an object of a database, and is a level of data virtualisation, known by and referred to as a derived table.  It achieves data encapsulation, and abstraction for the source table(s), and their structures.
 User Defined Function  A user-defined function is a programmable object of a database, and is an implementation of a virtual table.  When used, in a T-SQL statement, it can return  a tabular result-set, or scalar value to a calling object, or SELECT statement.  The T-SQL code of a user-defined function, cannot be dynamic SQL.
Stored Procedure  A stored procedure is a programmable object of a database, which comprises T-SQL statement(s) that can be dynamic SQL, and returns a tabular result-set, a scalar value, or an output parameter scalar value, to the calling object.  A stored procedure is executed, and cannot be part of a SELECT statement.
 <term>  <Description>

Citations

Ref. No.

Document or Site Name

Author

URL

Date Cited

Date Authored

 1.  Joson Mauss’ Blog Cabin  Jason Mauss  http://weblogs.asp.net/jamauss/articles/DatabaseNamingConventions.aspx  19 October 2012  13 May 2004
 2.  SQL Authority  Pinal Dave  http://blog.sqlauthority.com/2009/05/31/sql-server-create-multiple-filegroup-for-single-database/  22 October 2012  31 may 2009
3.  Database Files and File Groups  MSDN  http://msdn.microsoft.com/en-us/library/ms189563.aspx  22 October 2012  2012
4.  8 Steps to better Txn. Log Throughput  SQL Skills – Kimbely L. Tripp  http://www.sqlskills.com/blogs/kimberly/post/8-Steps-to-better-Transaction-Log-throughput.aspx  22 October 2012  25 June 2005
5. SQL Server: Myth About Primary Key And Clustered Key  PKumar3  http://www.bidn.com/blogs/pkumar3/ssas/2704/sql-server-myth-about-primary-key-and-clustered-key  22 October 2012  03 May 2012
6. General Naming Conventions MSDN – Microsoft http://msdn.microsoft.com/en-us/library/ms229045.aspx 22 October 2012 2010
7. ISO/ IEC 11179 WikiPedia http://en.wikipedia.org/wiki/ISO/IEC_11179 23 October 2012 21 January 2005
8. How are auto-created column statistics’ names generated? Paul Randall – SQLSkills http://www.sqlskills.com/BLOGS/PAUL/post/How-are-auto-created-column-statistics-names-generated.aspx 22 October 2012 14 August 2009
9. SQLBlog.com Alexander Kuznetsov http://sqlblog.com/blogs/alexander_kuznetsov/archive/2012/02/01/using-xact-abort-on-may-be-faster-than-using-try-catch.aspx 22 October 2012 01 February 2012
10. 4GuysfromRolla Pete Draigh http://www.4guysfromrolla.com/webtech/tips/t100901-1.shtml 25 October 2012 ?
11. MSDN Kimberly L. Tripp, Neal Graves http://msdn.microsoft.com/en-us/library/ms345124%28v=sql.90%29.aspx 25 October 2012 August 2006
12. Using Extended Properties on Database Objects MSDN – Microsoft http://msdn.microsoft.com/en-us/library/ms190243.aspx 25 October 2012 2008
13. Lynn Langit Lynn Langit http://lynnlangit.wordpress.com/2011/11/21/sql-server-2012sql-server-data-tools/ 25 October 2012 21 November2011
14. IT Knowledge Exchange Denny Cherry http://itknowledgeexchange.techtarget.com/sql-server/sql-clr-the-what-when-why-and-how/ 25 October 2012 10 January 2008
15. Simple-talk: CLR Assembly RegEx Functions for SQL Server by Example Phil factor http://www.simple-talk.com/sql/t-sql-programming/clr-assembly-regex-functions-for-sql-server-by-example/ 25 October 2012 15 April 2009
16. WikiPedia: Black model WikiPedia http://en.wikipedia.org/wiki/Black_model 25 October 2012 23 October 2012 23:04
17. SQLCLR.net: Determining when to use CLR Jonathan Kehayias http://www.sqlclr.net/Articles/tabid/54/articleType/ArticleView/articleId/5/Determining-When-to-Use-CLR.aspx 25 October 2012 05 April 2008
18. Regular vs, Context Connections  MSDN  http://msdn.microsoft.com/en-us/library/ms131104.aspx  26 October2012  2012
19.

The Real MCTS SQL Server 2008 Exam 70-433 Prep Kit: Database Design, Table 4.2, p170

 Valentine Boairkine, Mark Horninger, Herleson Pontes  http://books.google.co.za/books?id=5HqNdnPfQckC&pg=PA166&lpg=PA166&dq=%22SqlFunction%22+%22list+of+attributes%22&source=bl&ots=7l3x9G0xS6&sig=JSvzfcYhVXhZq-bV6TY7ne4JP_M&hl=en&sa=X&ei=HjKRUJfmH8iShgfapYHgAg&ved=0CDEQ6AEwAQ#v=onepage&q=%22SqlFunction%22%20%22list%20of%20attributes%22&f=false  31 October 2012  2008
20.  Attributes for SQL Server Projects and Database Objects  MSDN  http://msdn.microsoft.com/en-us/library/z28bh0b5(v=vs.90).aspx  14 November 2012  July 2008
21.
22.

Last Updated: 31 October 2012, 16h25