March 13, 2009 at 2:45 pm
I am trying to get a sql which checks if col1 data of Table A doesnt exists in TableB (col2) and in TableC(col3). Whats the better way of getting the sql using not exists/not in. Can someone please provide an input and how to get the sql correctly. TIA
March 13, 2009 at 3:42 pm
It will be easier for us to help you if you can provide us the table structure of the three tables in question; with sample data.
Thanks.
Mohit K. Gupta, MCITP: Database Administrator (2005), My Blog, Twitter: @SQLCAN[/url].
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March 13, 2009 at 3:59 pm
Please also show us what you've done. We don't want to be doing homework or exam questions without you trying. We'll help you figure out what's wrong.
March 13, 2009 at 10:46 pm
If you look at BOL (books online - the SQL Server Help function) you can find the format for both the EXISTS keyword and the IN keyword ... with EXAMPLES !!!
Both can be used with subqueries in this fashion:
IF (or WHERE) NOT EXISTS (select blah from table blahTbl where blahCol1 = blahCol2)
IF (or WHERE) blahCol2 NOT IN (select blahCol1 from table blahTbl)
If your question is simply which is the faster technique, here is some good reading.
http://www.sqlservercentral.com/articles/Performance+Tuning/2924/
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