Sql-Interview

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: Administration Level: Advanced

Question:

Your session is connected to a database named PublicWorks.

You want to create a temporary stored procedure, that only lasts until your session has ended. It should be available to all other sessions while your session is still active.

2025-03-23

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 need to add a new column to a table.

A developer insists that the column needs to be inserted into the middle of the existing table, not as a new column at the end.

2025-03-21

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 add a computed column to an existing table.

You then select from the table.

When is the value of the computed column calculated i.e., when the value is inserted or updated, or when the value is selected?

2025-03-19

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: Administration Level: Intro

Question:

You need to take an additional backup copy of a database to send to another site. You are considering using the Copy Only backup option.

What exactly is different about a Copy Only backup, compared to a Full backup?

2025-03-17

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: Administration Level: Medium

Question:

You need to add additional columns to a table. You are concerned that you do not want to lock the table for long periods. You plan to avoid any operation that would rewrite every row i.e., avoid whole of data operations.

2025-03-15

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 are reviewing stored procedures in the master database.

You note both Stored Procedures, and Extended Stored Procedures.

What is the difference between these types of procedures?

Answer:

Stored Procedures are written in T-SQL or SQL CLR and run in the standard user memory space of a SQL Server session.

2025-03-11

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 are writing a script to change the code in a T-SQL function.

You can choose to either DROP IF EXISTS and CREATE the procedure, or to use an ALTER statement.

What advantage would you get from using an ALTER statement?

2025-03-07

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:

A query included within a stored procedure, has a predicate written like this:

WHERE ISNULL(ProductSize, '') = ISNULL(@ProductSize, '')

A problem has been identified with this predicate. The system needs to be able to differentiate between NULL values for product size and blank strings. Currently both are treated as though they are the same.

2025-02-23

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: Security Level: Medium

Question:

With SQL Server on-premises, you can create a CREDENTIAL and they are stored in the master database.

What option do you have with Azure SQL Database?

Answer:

You can create a DATABASE SCOPED CREDENTIAL in both SQL Server and in Azure SQL Database.

2025-02-21

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:

When writing T-SQL code, you often need to replace NULL values. The core two functions provided are ISNULL and COALESCE.

What is the difference between them?

Answer:

ISNULL only takes a single value to check and replaces it when NULL.

2025-02-15