Re: If operator statements

On Thu, Jan 23, 2014 at 12:50:09PM +0500, Elyor Latipov wrote:
> Don't work this statement:
> IF NOT EXISTS (select TRUE from information_schema.constraint_column_usage where constraint_name='projects_pkey')
> THEN
> ALTER TABLE projects ADD CONSTRAINT projects_pkey PRIMARY KEY(id);
> END IF;

If you're running it as SQL command (for example in psql session) - it
will not work, as SQL doesn't have "IF" command.
IF is a command in PL/pgSQL, but to use it you have to either make
a function, or use:
DO $$....$$;
sql command.

Best regards,

depesz

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