Question

i’m looking for a way to delete records in table 1 with matching combinations in table 2 on ‘stn’ and ‘jaar’. The contents of column ‘jaar’ in table2 is formatted in a previous stage/query by

year(datum) AS ‘jaar’

Sorry, can’t find again the site where i found this “solution”.

DELETE FROM table1
WHERE stn, year(datum) IN (SELECT stn, jaar FROM table2);

Answer 1

You can achieve this using exists:

DELETE
  FROM table1
 WHERE exists(
           SELECT 1
             FROM table2
            WHERE table2.stn = table1.stn
              and table2.jaar = year(table1.datum)
       )