December 31, 2010 at 8:27 am
SQL Server Express 2008 R2, called from an Access front end.
I have a number of situations where I need to look at the results of a query and do something based on whether there are or are not any records in the resultset. I have tried SELECT TOP 1, but this seems to assemble the entire resultset first and then select only the first 1 (I think, anyway, I'm not that good at reading execution plans yet). Some of the queries return a large number of records and the resulting delay from calling them twice seems unnecessary to me.
I only want to know if there are or are not any records at all in the result and would like SQL Server to stop processing as soon as it can say "YES" to that question. Is SELECT TOP 1 the right approach or is there some better way to accomplish this? Is it even possible?
December 31, 2010 at 8:33 am
Typically to see if there are any rows you would use EXISTS.
IF EXISTS (SELECT 1 FROM <SomeTable>)
BEGIN
-- Some processing
END
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
December 31, 2010 at 10:23 am
GilaMonster (12/31/2010)
Typically to see if there are any rows you would use EXISTS.
IF EXISTS (SELECT 1 FROM <SomeTable>)BEGIN
-- Some processing
END
Yes, that was it - response time is instant.
Thank you.
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