IF ELSE vs CASE WHEN
Hi George,But this is not a stored procedure. They are just 2 statements: IF...ELSE construct and SELECT statement with CASE expression.No matter how you slice it, logically they should be consistent....
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Kalman,Think of it this way.... There are compile time errors and there are run-time errors. Syntactically, there is nothing wrong with:if exists(select name from sysobjects where name = 'myfunc')...
View ArticleIF ELSE vs CASE WHEN
It's an interesting topic. There' still more to it, though, and the IF statement definitely causes certain types of errors not to be detected under certain conditions (syntax always has to be valid...
View ArticleIF ELSE vs CASE WHEN
If the function does not exist, SQL cannot determine the return data type, and therefore throws the error. You should realize that the query engine makes this determination before the code is actually...
View ArticleIF ELSE vs CASE WHEN
Neil.W,(Just a guess) Both of these statement lies under T-SQL section. "If" is a part of procedural level programming that is enabled in SQL by MSft. Whenever you are using an "If" statement (as you...
View ArticleIF ELSE vs CASE WHEN
That's a great explanation and article, it's very accurate and true. I think it's a different topic though, because mixing data types in a Case statement yields the error message (in this case)...
View ArticleIF ELSE vs CASE WHEN
The explanation is this...SQL Server will always return the same data type regardless of which branch of the case/when expression is actually returned. In your case, one branch has a function call so...
View ArticleIF ELSE vs CASE WHEN
And to add a bit... It syntax checks, but doesn't execute the SQL, when the interpreter processes the Transact SQL, but an IF statement causes a line or block not to execute.Examples:if 1 = 2...
View ArticleIF ELSE vs CASE WHEN
See this blog postSQL Server Case/When Data Type problemsIt explains that even if the code is not supposed to be executed, it still executes.For every expert, there is an equal and opposite expert. -...
View ArticleIF ELSE vs CASE WHEN
The only explanation I can think of that 2 different project teams programmed it during the years.There is no T-SQL theoretical explanation for it.if exists(select name from sysobjects where name =...
View ArticleIF ELSE vs CASE WHEN
Number 1 is TRANSACT-SQL, running as a programming layer, and the flow of control determines what statements (including what SQL statements) get sent to the database engine. In number 1's case, the...
View ArticleIF ELSE vs CASE WHEN
Right - but the first condition fails so theoretically it should not try to execute the UDF.
View ArticleIF ELSE vs CASE WHEN
Thanks - but you are missing the point of the question. Assuming myfunc does not exist, why does the first statement work, but the second statement fails?
View ArticleIF ELSE vs CASE WHEN
You should be able to find the information from the definition. http://msdn.microsoft.com/en-us/library/ms181765.aspxYou cannot use CASE as a Flow Control method and the CASE eveluates its expression...
View ArticleIF ELSE vs CASE WHEN
You have not created any function with a name dbo.myfunc(). Create the function, it will resolve your error. create FUNCTION dbo.myfunc() RETURNS int AS BEGIN RETURN 100 END; select case when...
View ArticleIF ELSE vs CASE WHEN
you might want to add a "select" before that .. as the sql engine expects for a value in that particular position. When you have it as a subquery - the value is provided .. select case when...
View ArticleIF ELSE vs CASE WHEN
For CASE expressions all expressions should be of the same type or implicitly convertible types. Therefore I suspect it attempts to call this function in order to find out the return type.For every...
View ArticleIF ELSE vs CASE WHEN
Can someone explain why the first statement works, but the second one generates an error if myfunc() does not exist? 1) if exists(select name from sysobjects where name = 'myfunc') select...
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