[eftpotrm]

That sort of thing specifically, never actually tested it.

The last test I did help administer was for a VB+SQL job, and the first question was to write an example of a valid INNER JOIN. I'd say at maximum 25% of the candidates could do this.

Improving SNR? I did once have a potential employer get me to do a time-limited online test. If you wanted you could always stick your questions into one of them, so you can at least do the fizzbuzz-level screening without calling them in and sitting them down.

[tomjen3]

I think the reason you got so bad responses on the first question wasn't that they couldn't write the join statement but that they had heard the distinction between the different joins once in college and then never considered them again.

I bet that if you had asked for an example of a sql code which would list all the employees born before 1980 along with the department they worked for and the name of the head of that department, you would have gotten a much more useful result out of that.

That query is, incidentally, much more difficult to write.

[eftpotrm]

But with a normalised database you couldn't the above without two inner joins (and it's still a trivial query that any competent dev for that sort of position should be able to dictate while driving, it's that easy).

Really, if you can't remember the difference between inner, outer, full and cross joins then you shouldn't be working with databases. Which was rather what the test showed us, frankly.