SQL LIKE with no wildcards the same as '='?

sql wildcard sql-like
javamonkey79 picture javamonkey79 · Jan 1, 2009 · Viewed 18.9k times · Source

I know this is a pretty basic question, and I think I know the answer...but I'd like to confirm.

Are these queries truly equivalent?

SELECT * FROM FOO WHERE BAR LIKE 'X'
SELECT * FROM FOO WHERE BAR ='X'

Perhaps there is a performance overhead in using like with no wild cards?

I have an app that optionally uses LIKE & wild cards. The SP currently does the like and appends the wild cards -- I am thinking of just updating the query to use like but have the app append the wild cards as needed.

Answer

Christian C. Salvadó picture Christian C. Salvadó · Jan 1, 2009

As @ocdecio says, if the optimizer is smart enough there should be no difference, but if you want to make sure about what is happening behind the scenes you should compare the two query's execution plans.

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