Thread: SQL Query to get Column constraints

Hi there,

I have been through  the postgres faq's, and read through the describe.c
file.

I can't seem to solve my problem.

I am building an automatic file writer, that gives me information about each
of my tables.

What I need to know, is how to find out if a column is a primary, or part of
a primary key.  I need to do this using sql.

I am used to oracle, whose structure is different. Can anyone help me.

Whiel I am at it, If I can dynamically find out if a column has a sequence
attached to it, that would also be useful.

Regards

Steve

"Steve" <svanspal@bigpond.com> writes:
> What I need to know, is how to find out if a column is a primary, or part of
> a primary key.  I need to do this using sql.

In 7.3 this is pretty easy: look in the pg_constraint table for a 'p'
constraint for the table.  If you find one, 'conkey' lists the column
numbers of the key columns.  In prior versions you'd need to look in
pg_index instead.  (Actually the pg_index method still works, but it's
messier.)

See the "System Catalogs" chapter of the documentation.
        regards, tom lane