Our production environment consists of SQL Server 2008 R2 with several databases across multiple SQL Sever instances. We follow a somewhat old school approach to deployment, wherein once a project is past QA and in the Stage/UAT environment, we no longer create and deploy builds in a cumulative fashion. When bugs are found in Stage/UAT environment, the Builds to fix those bugs (iterative cycle) in Stage/UAT are preserved and deployed sequentially , as-is in Production as well. If we needed 10 iterations (hence 10 builds) to fix a bug in Stage/UAT, we will deploy the same 10 builds to Production sequentially !
This tediously meticulous approach to deployment guarantees the repetition of the same successful path to deployment in production (in theory), that was taken in Stage/UAT environment. It leads to same quality of code being deployed to production, as was deployed to Stage/UAT and hence is expected to produced the same results (in theory). However, when the number of iterations needed to fix all bugs in Stage/UAT is large enough that we routinely end up with builds running into double digits. Efficiently and accurately deploying 10 plus builds to production, within a relatively short deployment window was starting to become a challenge for us (Our DBA is not only expected to log deployment results, but proceed with next script ONLY upon success of previous script). While we were not ready to fully automate the execution of our deployment scripts via a batch run , we needed a command line method for deploying our SQL scripts relatively fast , where the execution messages are not only captured in a log file, but also displayed on the screen. This would not only let our DBA identify if a script’s execution encountered any errors, without having to open up the log file, but also help execute the deployment faster than using a fully manual, SSMS based deployment approach.
Our first attempt was using SQLCMD to achieve a fair degree of automation and speed up the deployment time, by reducing manual work. I have a simple test script here with a few PRINT statements , one simple SELECT statement that executes successfully and another simple SELECT statement that fails due to non-existent table (to simulate a script failure scenario). Do take note that my script uses SQLCMD variable “:on error exit” ,which causes the batch to stop execution upon encountering an error . I have named the script quite creatively as “test.sql”.
USE Demo; GO :on error exit PRINT N'Deploying Demo Script...'; GO SELECT COUNT(*) FROM [dbo].[demo_order]; GO PRINT N'Running query against non-existing table...'; GO SELECT COUNT(*) FROM [dbo].[does_not_exist]; GO PRINT N'This PRINT should not run as previous query errors and batch should exit...'; GO
When run in SSMS, this script produces the following output, and exits the batch upon encountering the first error as expected ;
Deploying Demo Script... (1 row(s) affected) Running query against non-existing table... Msg 208, Level 16, State 1, Line 2 Invalid object name 'dbo.does_not_exist'. ** An error was encountered during execution of batch. Exiting.
The quickest way to automate the execution of my test script, is to use SQLCMD via the command line. Note the “-b” option used in my SQLCMD command string, which forces the termination of batch upon encountering errors. This is functionally similar to using “:on error exit” SQLCMD variable within the script itself. Here is the simple command line string ;
sqlcmd -S WKS18176\SANIL_2012 -d Demo -b -i test.sql -o test.sql.log.txt
When this SQLCMD command string is executed in the command prompt, it created the log file documenting the error message and the fact that batch was terminated .However, note that the command prompt screen shows no indication of success or failure of the script.
Unless our DBA opens up the log file “test.sql.log.txt” for review, he cannot see the execution and error messages as seen below. (I could use the “type” command on the next line here but we prefer to have a single line command )
Changed database context to 'Demo'. Deploying Demo Script... ----------- 12 (1 rows affected) Running query against non-existing table... Msg 208, Level 16, State 1, Server WKS18176\SANIL_2012, Line 2 Invalid object name 'dbo.does_not_exist'.
This is where PowerShell came to our rescue. With minor modification to my SQLCMD command itself, and adding a PowerShell cmd-let, we were able to not only log the execution messages into a file, but also display them on the PowerShell screen, without losing any functionality related to exiting the batch upon error.
sqlcmd -S WKS18176\SANIL_2012 -d Demo -b -i test.sql | Tee-Object -file test.sql.log.txt
Here is a screenshot of executing my test script via PowerShell.
This was my first time using PowerShell and I am impressed how quickly we were able to learn and use it. Over the next few weeks, I am going to take up exploring PowerShell and learn how I can apply it to ease some more of our automation pain points !
- SQLCMD – http://technet.microsoft.com/en-us/library/ms165702(v=sql.105).aspx
- PowerShell – http://msdn.microsoft.com/en-us/library/dd835506(v=vs.85).aspx
With only a 9 weeks left until the end of the year, I figured I should start getting serious about meeting some of my goals for 2013. I did successfully complete my first goal for 2013 – speaking at the PASS Summit last week. My second goal for the year is to achieve the MCSA: SQL Server 2012 certification. Since I am Microsoft Certified (MCTS) on SQL Server 2008, I will be taking the two exams to transition to MCSA SQL Server 2012 – the 70-457 & the 70-458, instead of the usual 3 exams. However, in the absence of any training materials specifically geared towards these transition exams, I am using the standard training kit from Microsoft Press, to augment my real work experience on SQL Server 2012. The Microsoft Press training kit consists of 3 books, 1 each for exam 70-461, 70-462 & 70-463. These training kits are available on Amazon . I also happen to have a subscription to PluralSight’s training library, which has over 8 hours of training videos for exam 70-461 by christopher Harrison and over 16 hours of training videos for exam 70-462 by Sean McCown .
I am hoping that the combination of these two learning resources will help me prepare for the MCSA: SQL Server 2012 exam in about 90 days ( just over 12 weeks). My training schedule is inspired by Microsoft’s “90 Days to MCSA: SQL Server 2012 Edition” program. I intend to continue writing a weekly blog post that documents my learning and progress towards achieving the MCSA: SQL Server 2012 Certification. Hope to hear a lot of feedback and support from #sqlfamily on this journey !
We had great SQL Saturday #236, the second annual St.Louis SQL Saturday event, on Aug 3. As always, PASS plays a big role helping make any SQL Saturday event successful by providing the necessary infrastructure to run the event.
We moved the 2013 event to a different facility this year, the Wool Center at SLU. SLU provided the venue for this year’s event, as well as a few of their staff members to help us out on the day of the event. we could not have asked for any better. We definitely plan to continue host future St.Louis SQL Saturdays at SLU.
I would also like to thank the core team of organizers – Mike Lynn, Jay carter, Danielle Mayers and Kim Tessereau for putting in a lot of hard work to make this event possible. There’s also several volunteers who helped out at the registration desk, lunch line and classrooms, all of who deserve a big thanks. Organizing a successful SQL Saturday is definitely a team effort and I could not have asked for a better team for this event. No SQL Saturday event is possible with out the the speakers who contribute their time and skills , to present at the event. The generous support of all event sponsors plays an equally important role.
Last but the not the least, all the attendees who took the time to attend this event on a Saturday and are passionate about learning as well the SQL Community, deserve a big round of applause as well.
As organizers of the event, we noted a few improvements that can help us make the 2014 event even better;
1. Event Date – Quite a few of our regular local speakers, as well as several potential attendees could not make it to the event due to vacation plans. Several SQL Saturday organizers from the mid-west region had similar experiences in the months of July and August. We are planning for a event date in the month for September, for the 2014 St.Louis SQL Saturday.
2. Communication of Event start time and SpeedPASS – Though the first lecture for the day started at 9:30 AM and the registration desk opened at 8:30 AM, we had several attendees show up for the event before 8 AM. some of the sponsor representatives did not get the directions to the free parking lot We will definitely be much more clearer with our communication in the future. On the bright side, over 60% of the attendees came in with a printed SpeedPASS, which help the registration process move smoothly.
3. Lunch – We seem to have erred on the side of caution again while ordering lunch for the attendees, volunteers and sponsors. While we donated the left over lunch boxes to the building staff, we intend to plan the lunch orders better for the 2014 event.
4. After party – We intend to explore a venue closer to the SLU campus, for the after party for the 2014 event.
5. Recommended Hotel – While we were unable to secure a discount at the nearby hotels for the 2013 event, we intent to start negotiating with these hotel earlier for the 2014 event.
Please follow these links to the view the pictures taken during this event :
Please feel free to send us your feedback and suggestions to make the St.Louis SQL Saturday event better !
Please feel free to send us your feedback for the event.
Spring 2013 is shaping up to be a busy season for talking about SQL Server. So far I have an exciting line up of five sessions, scheduled for March and April of 2013
- On 3/8/2013 at noon MST, I will be talking about Service Broker, with the PASS Application Development Virtual Chapter. I am really looking forward to this one, only only because it will be first talk with a PASS Virtual Chapter, but also because the topic “Service Broker” is one of my favorites. This was the topic of my very first presentation at the SQL Saturday in Kansas City, back in 2010.
- On 3/9/2013 , I will be talking about Database Unit Testing with Visual Studio, at the Greater Midwest SQL Relay. Oakwood Systems organizes this annual conference in Spring and its a huge hit in St.Louis. If you are in the area, please do make time to attend this free full day event of top notch SQL Server Training.
- On 3/11/2013, I will be talking about Parameter Sniffing at the Capital Area SQL Server User group (PASS Local Chapter) in Albany, NY . I especially like this talk because I had learned about parameter sniffing while trying to tune a Query that was suffering from intermittent performance issues. Right around that time, I happened to come across Grant Fritchey’s chapter on the same topic in the MVP Deep Dives Vol.2 book . The content there in was so awesome, I decided to make a presentation out of it, and it has been a popular topic at several SQL Saturdays in the Mid-West region.
- On 3/26/2013, I will be talking about Database Unit Testing with VSTS, at the St.Louis Metro East .NET User group in O Fallon, IL . The first time I talked about this topic was at the St.Louis Days of .NET in Aug 2012 and I have noticed a renewed interest in this topic since the release of VSTS 2012.
- On 4/13/2013, I will be talking about Database Unit Testing with VSTS, at SQL Saturday #211 in Chicago, IL . SQL Saturday #31 (Chicago) in April of 2010 was the very first SQL Saturday I attended and it got me involved with the SQL Server Community. Its a huge honor for me to be selected to speak at the 2013 Chicago SQL Saturday and I am looking forward to this trip !
Understanding the numerous types of variable SQL Server has to offer, and their appropriate usage is one of the cornerstones of developing effective database code. I recently helped a co-worker fix an error message in his code.
-- Error Msg 137, Level 15, State 2, Line 3 Must declare the scalar variable "@l_INT".
The code snippet looked something like this, which led to a discussion about scope of T-SQL variables and an interesting way to fix this problem.
CREATE TABLE #scope_test1 (col1 INT); CREATE TABLE #scope_test2 (col1 INT); GO DECLARE @l_INT INT = 42; INSERT INTO #scope_test1 (col1) SELECT @l_INT; GO INSERT INTO #scope_test2 (col1) SELECT @l_INT; GO
T-SQL language supports local variables (their names begin with a single @). The scope of a variable is the range of Transact-SQL statements that can reference the variable. The scope of a variable lasts from the point it is declared until the end of the batch or stored procedure in which it is declared. A T-SQL batch is a group of statements that SQL Server parses as a single unit. A batch can be delimited by the BEGIN..END statements, or a client tool like SQL Server Management Studio (SSMS) can specify the end of a batch with a GO command (you can set any word to be a batch separator in SSMS, but we will leave that discussion for another time). The names of some Transact-SQL system functions begin with two at signs (@@). They are commonly referred to as Global variables. Global variable names begin with a @@ prefix. You do not need to declare them, since the server constantly maintains them. They are system-defined functions not variables and do not have the same behaviors as variables. All the global variables represent information specific to the server or a current user sessions. Some of the commonly used ones are @@ERROR, @@IDENTITY, @@VERSION. Traditionally, DECLARE command is used to declare a local variable and SET or SELECT used to initialize its value. With SQL Server 2012, both of these tasks can be accomplished in a single statement ;
DECLARE @MyCounter INT = 12 ;
The variables we discussed so far are scalar variables, which can hold a single data value of a specific type. A table variable is a special data type that can be used to store a result set for processing at a later time. table is primarily used for temporary storage of a set of rows returned as the result set of a table-valued function. Functions and variables can be declared to be of type table. table variables can be used in functions, stored procedures, and batches. A DECLARE statement (similar to local scalar variables) is used to DECLARE a table variable. While they behave exactly like local variables, with a well defined scope,they can be thought of as being similar to temporary table, but with several limitations.
The SQLCMD utility lets you enter Transact-SQL statements, system procedures, and script files at the command prompt, in Query Editor in SQLCMD mode, in a Windows script file or in an operating system (Cmd.exe) job step of a SQL Server Agent job. This utility uses ODBC to execute Transact-SQL batches. Scripting variables can be used in SQLCMD scripts. Scripting variables enable one script to be used in multiple scenarios. The setvar command is used to define scripting variables. Variables that are defined by using the setvar command are stored internally. Scripting variables should not be confused with environment variables that are defined at the command prompt by using SET.
The scope of a SQLCMD scripting variable can span several batches, which can be used to implement variables that don’t go out of scope even when a batch ends. The example below is a simplified demo of the same ;
:setvar l_int "42" CREATE TABLE #scope_test1 (col1 INT); CREATE TABLE #scope_test2 (col1 INT); GO INSERT INTO #scope_test1 (col1) SELECT $(l_int); GO INSERT INTO #scope_test2 (col1) SELECT $(l_int); GO -- Results (1 row(s) affected) (1 row(s) affected)
A review of the types of variables the T-SQL language has to offer, has helped refresh my understanding of their appropriate usage.
- Table Variables – http://msdn.microsoft.com/en-us/library/ms175010.aspx
- T-SQL Variables – http://msdn.microsoft.com/en-us/library/ms187953(v=sql.105).aspx
- Global Variables – http://www.codeproject.com/Articles/39131/Global-Variables-in-SQL-Server
- Scripting variables with SQLCMD – http://msdn.microsoft.com/en-us/library/ms188714.aspx
- SQLCMD utility – http://msdn.microsoft.com/en-us/library/ms162773.aspx
SQL Saturday #122 | Louisville, KY on July 21, 2012 was the 5th SQL Saturday I have attended so far, and my 3rd as a speaker. The St.Louis contingent – Kathi Kellenberger, Kim Tessereau, Mike Lynn, Jay Carter, Cindy Baker and me ! – was especially excited to attend this event, not only because it’s organized by our friend Malathi Mahadevan, but also for a chance to escape the St.Louis heat !
We had almost forgotten about the time zone change when we drove into Louisville at 6 PM Central sharp, only to realize we were an hour late for the speakers’ dinner! The Bristol Bar & Grille was the perfect location for a great speakers’ dinner, and gave us all a chance to relax, network and enjoy some good food (My personal favorite was the Espresso Crème Brûlée).
University of Louisville is a short 10 minute drive from the Marriot Hotel, and thanks to the email notifications with directions, as well as plenty of signs, we had no trouble finding the venue. Thanks to SPEEDPASS, there were no lines at the registration desk and I found they had my favourite Asiago Cheese Bagels for breakfast! My first session for the day was Andy Thiru‘s “SQL Azure Intro and What’s New” session and it surely exceeded my expectations. I have never had the opportunity to work with SQL Azure so far, and this session gave me the knowledge and tools to get me started on my own. The next session on my list was “What Sequence objects are (and are not)” by Louis Davidson. I used to be an Oracle DBA until a few years ago, and took sequences for granted, until I discovered SQL Server doesn’t have them (until 2012). With their introduction in SQL Server 2012, I took this opportunity to get myself reacquainted with Sequences.
I had some delicious Veggie Wraps and a Cookie for lunch – again, no lines and no waiting! Post lunch, I took a break in the Speakers’ Lounge to review my upcoming session on Parameter Sniffing, where I discovered a cooler full of Ice Cream! I had to stop myself after two servings and got back to reviewing my slides & checking my demos. A majority of the attendees for my session were quite involved with the topic, giving rise to several discussions and Q&A, thus making my session all the more valuable for everyone in the room. I was really pleased with the generous evaluations and great feedback for my session.
The last session of the day for me was “Bulletproof: Hardening your SQL Server from Attack” by Sarah Barela. As a developer, I take care of hardening my code against SQL Injection, but usually let administrators worry about securing the servers and databases. This session revealed the amount of work administrators (Database, Server as well as Network) put in to secure our servers ! After the last session, it was time for the closing ceremonies and Raffle. The SQL Saturday #122 Team hosted a great event with a full day of valuable SQL learning. I am really thankful to the SQL Saturday #122 Team for giving me the opportunity to present my session, and the support of all the sponsors to making such events possible.
I am looking forward to see my friends from Louisville again, at SQL Saturday #154 in St.Louis on Sept 15th , the very first SQL Saturday in St.Louis !
While brushing up on my knowledge of software testing concepts, I came across quite an amusing definition of testing; “To tell somebody that he is wrong is called criticism. To do so officially is called testing” . A programmer usually resents it when a tester finds a defect in his code. We programmers thoroughly unit test our code before handing it off to a tester, because we take pride in developing a bug free application. Some programming languages (C# , VB, ASP.NET) afford themselves to be unit testing easily, because the application is developed within Visual Studio and can readily leverage its unit testing framework.
Visual Studio allows you to create Database projects, and database developers have started embracing it since Visual Studio Team Systems 2008 Database Edition GDR. This offers a robust framework for database developers to identify bugs with their database objects (schemas, stored procedures, functions, etc) by unit testing their database (T-SQL) code, before handing it over to the tester. Before we jump into the specifics of database unit testing with Visual Studio, the next couple of paragraphs warm us up to the topic by covering a few basic concepts of software testing.
Software testing, undoubtedly plays a important role in the life cycle of most IT Projects. The Goal of any type of software testing is to identify defects to be fixed, so that the product meets requirements and has a deterministic and predictable output. Depending on the testing method employed, testing can be implemented at any time in the development process. Different software development models will focus the test effort at different phases in the development process. Newer development models, such as Agile, often employ test driven development and place an increased portion of the testing in the hands of the developer, before it reaches a formal team of testers.
Software testing methods are traditionally divided into white and black-box testing. These two approaches are used to describe the point of view that a test engineer takes when designing test cases. Unit Testing falls under the category of white box testing, where the the tester has access to the internal data structures and algorithms, including the code that implements these. This is in contrast with the black-box testing method, which treats the software as a “black box”—without any knowledge of internal implementation. A black box tester is usually not a programmer, and aims to only test the functionality of software according to the applicable requirements. Since the black-box tester has no knowledge on the underlying code, he may find bugs that a programmer misses. However, the same principle can sometimes lead to writing inefficient or incomplete test cases.
Unit Testing is a key component of Test driven development (TDD). Unit Tests are usually written by Developers while they work on the code, to ensure that a specific of piece of code (Function, Class, Stored procedure, etc) is working as expected. Unit Testing helps to identify defects in the earlier stages of the software development life cycle, where they are cheaper to fix. Unit Testing can prove especially challenging in the world of database development, because of the need for a consistent test environment.
Database Unit Tests are used to establish a baseline state for a database and then to verify any subsequent changes that you make to database objects. The Unit Testing Framework in Visual Studio (starting with VSTS 2005) helps database developers create, manage and execute Unit Tests for a Database. The Microsoft.VisualStudio.TestTools.UnitTesting namespace supplies classes that provide unit testing support. This namespace contains many attributes that identify test information to the test engine regarding data sources, order of method execution, program management, agent/host information, and deployment data. It also contains custom unit testing exceptions.
You will need the Database Edition GDR of VSTS 2008 or the Ultimate (or Premium) Editions of VSTS 2010 to create, modify and run database unit tests. You can run database unit tests with Professional Edition on VSTS 2010, but cannot create or modify them. Before you can start running database unit tests in VSTS, you must first create a Database Project and then create a test project. The next step is to write sets of Transact-SQL tests that exercise your database objects. Executing these tests in your isolated development environment helps you to verify whether those objects are behaving correctly before you check them in to version control. As changes are made to the database schema, you can use these tests to verify whether the changes have broken existing functionality. A detailed step by step walk through for creating and running database unit tests can be found here on MSDN . Once Created, a Unit Test Project and of the tests will show up in the Solution Explorer View;
In a typical database unit test, a Transact-SQL test script runs and returns an instance of the ExecutionResult class. The instance of this class contains a DataSet, the execution time, and the rows affected by the script. All of this information is collected during execution of the script. These results can be evaluated within the Transact-SQL script by using the RAISERROR function, or they can be evaluated by using test conditions. Visual Studio Premium provides a set of the following predefined test conditions for you to use;
- Data Checksum
- Empty Resultset
- Execution Time
- Expected Schema
- Not Empty Resultset
- Row Count
- Scalar Value
- Run multiple unit tests as a group
- Run tests as a part of a Build
- Enforce check-in policy
- Software Testing Principles, Terminology & Definitions - http://en.wikipedia.org/wiki/Software_testing
- Unit Testing Framework in Visual Studio -
- Database Unit Testing with Visual Studio -
- Unit Test Conditions in Database Unit Tests - http://msdn.microsoft.com/en-us/library/aa833423
- Test Lists - http://msdn.microsoft.com/en-us/library/ms182461.aspx
- Visual Studio 11 (Beta) Unit Testing updates – http://blogs.msdn.com/b/visualstudioalm/archive/2012/03/08/what-s-new-in-visual-studio-11-beta-unit-testing.aspx
- Software Testing Jokes – http://softwaretestingfundamentals.com/software-testing-jokes/