I'm trying to update a tablecolumn based on another value inside this table but I keep getting an error.
My query is as follows:
    UPDATE partcreditor 
    SET partcreditor.creditorid = creditor.creditorid
    FROM partcreditor
    INNER JOIN creditor ON partcreditor.creditornr = creditor.creditornr
    WHERE creditor.relgroupid = 1
    AND creditor.creditortypeid = 1
 
    