Question

Question

How can I alter the SQL code below to ensure that the inserts into "dbo.tblBootStrapperInstruments" only occur if they don’t already exist?

Code

INSERT INTO dbo.tblBootStrapperInstruments (CCY, Instrument, Tenor)
SELECT CCY,Instrument,Gridpoint FROM dbo.Feed_Murex_Intraday_DF mx WHERE NOT EXISTS 
(SELECT * FROM dbo.tblBootStrapperInstruments bs
WHERE bs.CCY = mx.CCY
AND bs.Instrument = mx.Instrument
AND bs.Tenor = mx.Gridpoint) 

Answer 1

Here’s how I’d do it.

INSERT INTO dbo.tblBootStrapperInstruments (CCY, Instrument, Tenor) 
SELECT mx.CCY,mx.Instrument,mx.Gridpoint FROM dbo.Feed_Murex_Intraday_DF mx
LEFT OUTER JOIN dbo.tblBootStrapperInstruments bs 
ON bs.CCY = mx.CCY 
AND bs.Instrument = mx.Instrument 
AND bs.Tenor = mx.Gridpoint
WHERE bs.CCY IS NULL