r == richard.broersma@xxxxxxxxx writes: r> On Thu, Jun 4, 2009 at 1:23 PM, Brandon Metcalf r> <brandon@xxxxxxxxxxxxxxxxxx> wrote: r> > Got it. Currently, it doesn't have a column for an ID, but I can add r> > one if this is the only way. r> Actually any column with a unique index on it will work. It doesn't r> have to be primary key or even a serial id. r> ANSI-SQL 92 allows for the following syntax: r> CONSTRAINT Only_one_row r> CHECK( 1 >= (SELECT COUNT(*) FROM _this_table;)); r> However, I have yet to find a RDBMS (PostgreSQL included) that r> supports select statements in a table's check constraint. I had thought about a subquery in the constraint, but as you say, that didn't work. Thanks for the help. -- Brandon -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
