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laailalalaa
Yak Posting Veteran
57 Posts |
 Posted - 2010-05-09 : 14:34:07
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| i know the following is true in many programming languages, please confirm whether this also applies to t-sql:IF condA OR condB OR condCTHEN ...condC will be evaluated only if both condA and condB fail, right?thanks |
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SwePeso
Patron Saint of Lost Yaks
30421 Posts |
Posted - 2010-05-09 : 15:19:25
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It depends on what the boolean checks are.SQL Server treats all operators in terms of costs. In you example, SQL Server may very well try condC first!
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laailalalaa
Yak Posting Veteran
57 Posts |
Posted - 2010-05-09 : 15:24:05
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| got it, thanks Peso |
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ms65g
Constraint Violating Yak Guru
497 Posts |
Posted - 2010-05-09 : 15:27:43
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It is not equivalence?IF condA --THENELSE IF CondB --THEN ELSE IF CondC --THEN |
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SwePeso
Patron Saint of Lost Yaks
30421 Posts |
Posted - 2010-05-10 : 01:27:10
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No.If condA is considered more costly to evaluate, condC may be evaluated first. Or condB. And condA last.
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ms65g
Constraint Violating Yak Guru
497 Posts |
Posted - 2010-05-10 : 06:14:19
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| Thanks Peso,Could you please give me a link for reference for this subject? |
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SwePeso
Patron Saint of Lost Yaks
30421 Posts |
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ms65g
Constraint Violating Yak Guru
497 Posts |
Posted - 2010-05-10 : 14:38:40
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| Thanks, but link do not word for me. Not implortant |
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SwePeso
Patron Saint of Lost Yaks
30421 Posts |
Posted - 2010-05-14 : 00:40:20
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quote:
Hi,You already posted about cost based.I want to know WHEN clauses in CASE are evaluated in order or not?
In a CASE statemnt, the clauses are always evaluated in the order they are written, until one is found true.
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OR operator