troubleshooting Question

Complicated SQL Query?

Avatar of ookjar
ookjar asked on
7 Comments1 Solution368 ViewsLast Modified:
Ok here's the question, sorry if it has already been answered I found one which nearly worked but my problem goes one stage further, so anyone with any ideas would be much appreciated...

I have the following table:-

itemkey  |registrationNumber | subjectID | subjectLevelsID
   1     |       29          |    21     |      KS3
   2     |       29          |    22     |      KS2
   3     |       26          |    26     |      KS1
   4     |       21          |    18     |      KS1
   5     |       21          |    22     |      KS3
   6     |       21          |    21     |      KS2


I need a query to return all registrationNumbers whose (subject ID = 21 and subjectLevelsID = KS3 AND subjectID=22 AND subjectLevelsID = KS2) i.e. registrationNumber 29.

or multiple iterations thereof, i.e. subjectID and subjectLevelsID are AND'ed


SELECT registrationNumber
FROM teacherskills
WHERE subjectID in (21,22) and subjectLevelsID in ("KS3")
group by registrationNumber
having count(*) = 2

This works for subjectID, but only for 1 subjectLevelsID if I put more in the in clause i.e. ("KS3","KS2") then it doesn't matter which subject corresponds, which is not what I want to achieve.

I hope this makes sense as to what I'm trying to achieve, i really do not want to change the table structure to have a finite number of subjectID's and Levels in the same row... rather defeats the object of a relational database!

b.t.w the database I'm using is mySQL, so joins are very limited!

Please help anyone!


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