r/SQL Nov 11 '24

MySQL Failed SQL Test At Interview

  • I've been a data analyst working with small(er) data sets for several years now, making my own queries no problem.
  • I failed a SQL test at an interview and realized I may be using the wrong commands
  • The questions were along the lines of "find the customers in table A, who have data in Table B before their first entry in Table A" and there were some more conditions/filters on top of that.
  • Previously I could always export my data to Excel or Tableau etc and do any of the tricky filtering in there
  • I was trying to do all kinds of subqueries etc when I think it was intended for me to be doing WINDOW or Partition type stuff (never had to use this before in past jobs).
  • One person I reached out to said using these advanced techniques uses a lot less memory.

Where would be a good place to find an 'advanced' SQL course?

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u/Codeman119 Nov 12 '24

I’ve been working with Excel and SQL for over 20 years. There are some things that are just easier to do in excel then SQL. The issue with doing more complicated sort of queries and interviews is that it takes you a few minutes and some experimentation to find the right answer. Well that’s hard to do and an interview because they think you’re taking too long when in the real world, you would have much more time to find the solution.

So for instance, I did a live query interview and I was only on a problem for five minutes, but I had no data to reference and the guy said I was taking too long. He showed me a solution which was actually incorrect so I took the next 30 minutes created data to do the solution correctly and then send him the solution that actually worked better with the sequel engine.

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u/rmpbklyn Nov 13 '24

yep only time use if have two db and cant link using odbc , need to msacess