Re: Truncate if exists

Robert Haas escribió:
> On Thu, Oct 11, 2012 at 3:22 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> > So we just need a function called pg_if_table_exists(table, SQL) which
> > wraps a test in a subtransaction.
> >
> > And you write
> >
> > SELECT pg_if_table_exists('foo', 'TRUNCATE TABLE foo');
> >
> > and we can even get rid of all that other DDL crud that's been added....
> >
> > and we can have pg_if_table_not_exists() also.
>
> You could make this more composable by having pg_table_exists() and
> pg_execute_sql_from_string(). Then you can write: SELECT CASE WHEN
> pg_table_exists(...) THEN pg_execute_sql_from_string(...) END. And if
> you want the if-not-exists case then just stick a NOT in there. And
> if you want a more complicated condition, you can easily write that as
> well.

Uh, we had an execute() function of sorts in the extensions patch; that
seems to have been ripped out. Do we want it back?

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