This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.
Section: Developer Level: Medium
Question:
You have a value in a variable named @NewValue. The data type is varchar(20).
You want to check if the value in the string is an integer and could be cast to an integer.
2025-05-06
Now that I’ve finished posting my T-SQL 101 series, it’s time to start another blog post series.
A few years back, I created a shortcuts series that covered how to use SQL Server Management Studio (SSMS) proficiently. I eventually added that all into a free eBook. It was updated in March 2019.
You can get a copy of it here:
SSMS version 21 is a huge shift from previous versions, so I thought it was time to revisit all the tips and tricks, to work out what still does or doesn’t work, and to add a bunch of new ones. V21 is based on the 64 bit version of Visual Studio, not the older 32 bit VS partner edition shell.
2025-05-05
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.
Section: Developer Level: Intro
Question:
You want to call a procedure that counts the number of customers in a particular city.
You use the following code:
DECLARE @NumberOfCustomers int;
EXEC dbo.GetNumberOfCustomers
@City = N'Brisbane',
@NumberOfCustomers = @NumberOfCustomers;
SELECT @NumberOfCustomers;
No matter which city name you pass in the code, the selected count is NULL.
2025-05-04
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.
Section: Developer Level: Medium
Question:
You have a series of very similar SQL queries in an application.
You notice that one of them includes an OPTION LABEL clause.
What would this be used for?
Answer:
OPTION LABEL allows you to apply a label to an instance of a query. That then makes it easy to trace executions of the query using tools like Extended Events or SQL Server Profiler.
2025-05-02
Just a heads-up that v25 of SDU Tools went out to SDU Insiders last week. If you haven’t used SDU Tools, they are just a large library of functions implemented in T-SQL. You can use them as a full library or use them as examples of code in work you are trying to do.
We’ve also tried to keep all the code working for all versions of SQL Server that we see clients using. That means from SQL Server 2008 to SQL Server 2022. We also have an Azure SQL DB version.
2025-04-30
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.
Section: Administrator Level: Medium
Question:
Your team is considering a design where a small number of tables would each have a very large number of columns.
One developer has suggested making the columns SPARSE where another has suggested just making them NULLable.
2025-04-28
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.
Section: Development Level: Advanced
Question:
You have a table in your database that contains six columns that are defined with the text data type.
When you run checks on your database, these columns are often flagged with deprecation warnings, and so you change each column as follows:
2025-04-25
I’ve been meaning to write about this book for quite a while. Complete Showplan Operators by Fabiano Amorim is a wonderful book, and a great example of the books that our friends at Red-Gate have made available for free, over the years, as part of their Simple Talk series.
Clearly, reading execution plans in detail isn’t for everyone, but any developer working with SQL Server should be across much of this content.
2025-04-24
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.
Section: Development Level: Medium
Question:
You have a column in your database that is defined as char(20). Whenever you query it, 20 characters are returned, with space padding any unused characters.
An administrator has suggested applying ROW compression to the table, to save space and improve performance.
2025-04-23
Over the years, I’ve done some work with Snowflake. In fact, I got certified in it at one point, and I’ve stayed across its capabilities. I have friends that work there.
Overally, I found the SQL language that Snowflake offered to be pretty limited, and particularly at the time I spent the most time on it, it seemed to have gaps in what it provided.
One thing that fascinated me though was the idea of an anonymous stored procedure.
2025-04-22