Re: Actual expression of a constraint

lrotger <lrotger@aircomp.aero> writes:
> I know I could dig this out of the manuals so don't be too hard on me,
> I'd like to know how to query the actual text of the expression of a
> constraint. I know the name of the constraint and of the table.

Something like this:

regression=# create table t1 (f1 int constraint c1 check (f1 > 0));
CREATE TABLE
regression=# select pg_get_constraintdef(c.oid)
regression-#   from pg_constraint c join pg_class t on c.conrelid = t.oid
regression-#   where t.relname = 't1' and c.conname = 'c1';
 pg_get_constraintdef
----------------------
 CHECK ((f1 > 0))
(1 row)

You can probably also get it from the information_schema.

            regards, tom lane