We sometimes help clients interview DBAs and Developers for their team. Requirements vary depending by position, but sometimes it’s important to test a candidate’s TSQL skills.
While I can test candidates thoroughly on strategies for TSQL (when they’d use certain constructs, the pros and cons of various approaches), if what you care about is skills writing complex TSQL there’s one surefire test: a lab.
The first step is to pick your dataset and environment, then dream up the TSQL query you’d like your candidate to write. Next, test it with one of your own staff members and make sure the problem is suitable for the job you’re trying to fill.
But you may not want to give candidates access to your production, or even development data — after all, they don’t work for you yet.
Good news, there’s an easy way to do this online! Check out the Stack Exchange Data Explorer. You can assign the candidate a query to write using this tool online.
How to make it work:
- This only works for in-person interviews. Because human nature.
- You’re going to need a moderator and at least 30 minutes, because the candidate will need to figure out the schema.
- A history of queries is kept in the tool. You’ll need to let them know they can’t search that history, and it’s up to you if you’re going to let them use Books Online (hey, we all use it in the real world).
If you don’t want to deal with the hassle of the query history online, you can always download a copy of the Stack Overflow database and set up your problem on a locally installed test instance of SQL Server, too.
The secret test: if your candidate likes writing TSQL, they’re going to love the challenge and it will energize them.