test if a query is valid or not

[Anon]

Hi all,
I have a database in postgresql and I am building a simple expression builder in php for the users to filter a result set based on the expression they create in the expression builder. Now how do I test that the expression that was built when put in a sql query will not result in some error messages from the backend. In other words how do I test if a query is a valid query without seeing the error messages returned to the php by postgresql.
Thanks
Rachit

[Anon]

Here's something to try - $sql is the candidate query:

if(@pg_exec($connection, "EXPLAIN $sql"))
{...valid query...}
else
{...invalid query - error accessible from pg_errormessage()
}

@ suppresses the error message, EXPLAIN prevents the query from actually going ahead prematurely.

That's what I'd try first. It won't work if EXPLAINed queries return false for some reason.