Re: Actual expression of a constraint

Tom Lane wrote:
> 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
>

I forgot to mention that my version is 7.2.1. I replaced the column
names for the ones I see in my installation hoping it would work but the
function, pg_get_conbstraintdef() doesn't exist.

I see that information_schema was introduced in 8.0 too.

Anyway I found out that \d table shows the table definition so it's solved.

Thanks a lot
L Rotger