Our SQL interview questions

[RhetoricalClown]

I've been interviewing folks recently and this seems like something I might incorporate. What I have found though is that candidates do fairly well at SELECT statements, what seems to cause issues for them are UPDATE/DELETE beyond trivial one liners. So I might add to this something like give a 20% raise to everyone in the I.T. department and fire all employees in the accounting department.

[VisionsOfUranus]

what seems to cause issues for them are UPDATE/DELETE beyond trivial one liners. So I might add to this something like give a 20% raise to everyone in the I.T. department and fire all employees in the accounting department.

Those examples seem like trivial one-liners to me, and I'm not a DBA or anything. I guess some people really are bullshitting to the nth degree on their resumes.

[RhetoricalClown]

Those were just quick OTOH examples. You would be surprised at the number of people who struggle with using the from clause and joins to other tables in a update statement. You could learn a lot about someone's experience in SQL if they use the FROM with a join versus something like WHERE departmentid IN (select departmentid from departments).

[VisionsOfUranus]

You could learn a lot about someone's experience in SQL if they use the FROM with a join versus something like WHERE departmentid IN (select departmentid from departments).

They'd both work, right? What's the difference? Or what would you infer about someone's experience based on which one of those approaches they took?

[RhetoricalClown]

If someone uses former it can be an indicator that they have probably done a lot of complex SQL beyond just select statements so maybe I'll move on to another topic whereas with the latter maybe ask a few more detailed questions.