I have done something like this:
Insert INTO TrustChecks (
CheckNumber,
Amount,
ClearedDate,
ClearedStatus)
SELECT
ClearedChecks.CheckNumber,
ClearedChecks.Amount,
ClearedChecks.CheckDate,
'C'
FROM ClearedChecks
Left Join TrustChecks
On TrustChecks.CheckNumber = ClearedChecks.CheckNumber
where TrustChecks.CheckNumber is NULL
Only inserts the entries from...