How to select DISTINCT rows without having the ORDER BY field selected
- by JannieT
So I have two tables students (PK sID) and mentors (PK pID). This query
SELECT s.pID
FROM students s JOIN mentors m ON s.pID = m.pID
WHERE m.tags LIKE '%a%'
ORDER BY s.sID DESC;
delivers this result
pID
-------------
9
9
3
9
3
9
9
9
10
9
3
10 etc...
I am trying to get a list of distinct mentor ID's with this ordering so I am looking for the SQL to produce
pID
-------------
9
3
10
If I simply insert a DISTINCT in the SELECT clause I get an unexpected result of 10, 9, 3 (wrong order). Any help much appreciated.
