CHECK constraint based on UDF should be enough. something likeCREATE FUNCTION DateValidate(@Date datetime,@EventID int)RETURNS bitASBEGIN DECLARE @Ret bit,@StartDate datetimeSELECT @StartDate = StartDateFROM EventsWHERE EventID = @EventIDSELECT @Ret = CASE WHEN @Date > @StartDate THEN 0 ELSE 1 ENDRETURN (@Ret)ENDALTER TABLE Payment ADD CONSTRAINT Chk_PaymentDate CHECK (dbo.DateValidate(PaymentDate,EventID) = 1)
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