Re: conditional FROM

Richard Klingler <richard(at)klingler(dot)net> wrote:

> Good day...
>
> I'm trying to build a query for PGSQL 9.1 where a table has two
> references with only one being used depending of the type of entry..
>
> For example, the table has following simplified structure:
>
> portid primary key
> port2node index to table node
> port2card index to table card
>
> So how can I do a conditional FROM clause in the query depending on the
> column port2node and port2card?
> If port2card is Null or 0 I don't want it in the FROM clause as the
> query will return unneccessary duplicate
> row...the same goes for port2node being Null or 0...

I think, you can't do that, you have to build your query and execute
that string. You should use a function to do that.

Andreas
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