Possible Duplicate:
oracle insert if row not exists
I am using the query below to calculate a total for some data, however, I want the insert to only be executed if the ID doesn't exist in the EL_CLIENT_REC_UNITS in the first place. Can anyone see a way of doing this?
INSERT INTO EL_CLIENT_REC_UNITS
(ID,
EL_CLIENT_ID,
RECORDING_ID,
UNIT_TYPE,
PHY_DIG_OR_TOTAL,
CONTROLLED_PERCENTAGE,
PERC_ADJ_UNITS_RECEIVED,
SUM_UNITS_RECEIVED) (
(SELECT
EL_CLIENT_ID||RECORDING_ID||'CT' AS ID,
EL_CLIENT_ID AS EL_CLIENT_ID,
RECORDING_ID AS RECORDING_ID,
UNIT_TYPE AS UNIT_TYPE,
'Total' AS PHY_DIG_OR_TOTAL,
NULL AS CONTROLLED_PERCENTAGE,
SUM(PERC_ADJ_UNITS_RECEIVED) AS PERC_ADJ_UNITS_RECEIVED,
SUM(SUM_UNITS_RECEIVED) AS SUM_UNITS_RECEIVED
FROM EL_CLIENT_REC_UNITS
WHERE EL_CLIENT_ID = pRow.ID
AND UNIT_TYPE = 'Cleared'
GROUP BY UNIT_TYPE, EL_CLIENT_ID, RECORDING_ID)
WHERE NOT EXISTS (SELECT );