Re: BUG #13973: Constants resolved in then/else clauses

harry(dot)townsend(at)eflowglobal(dot)com wrote:
> The following bug has been logged on the website:
>
> Bug reference: 13973
> Logged by: Harry Townsend
> Email address: harry(dot)townsend(at)eflowglobal(dot)com
> PostgreSQL version: 9.1.20
> Operating system: Windows Server 2008
> Description:
>
> I attempted to create a safety check in a query using a "case when"
> statement such that if the condition evaluated to false, it would return (1
> / 0) in order to nullify the entire transaction. With small conditions, this
> works fine. With larger ones, it seems that the constants in the "else"
> clause (didn't test for "then" clause) are evaluated before the condition,
> causing it to fail every time. If the "else" part requires a column value,
> it seems to force the condition to evaluate first though.

Can you show a complete example?

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Álvaro Herrera http://www.2ndQuadrant.com/
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