Move the where clause on cashvalue2 to the join. Also, account for cashvalue2 being null - see changes in red below.INSERT INTO accountvalues ( account, TYPE, date, cashreturn, cashvalue )SELECT a.account, 'totalcash' AS TYPE, a.date, a.cashreturn, SUM(a.cashvalue + COALESCE(b.cashvalue,0)) AS cashvalueFROM accountvalues a LEFT JOIN accountvalues b ON a.account = b.account AND a.date = b.date AND b.type = 'cashvalue2' WHERE a.type = 'cashvalue1'