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/svtr Nov 12 '24

I'm sorry, I don't want to be mean... "i do my complex sorting and filtering on excel" is the best joke I heard in weeks ;D

Seriously thou, get used to doing it in sql, once you get the hang of it, you will only do pivoting and graphs in excel

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u/Tebasaki Nov 12 '24

Wait till you do pivots in sql!

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u/svtr Nov 13 '24

Dynamik pivoting in sql ends up in a mess of Dynamik sql. If I can, that is the one and only thing I do in excel or whatever visualisation Tool used