On 07/22/2013 07:16 AM, Vik Fearing wrote:
On 07/22/2013 04:05 PM, ldrlj1 wrote:
Postgres 9.2.4.
I have two columns, approved and comments. Approved is a boolean with no
default value and comments is a character varying (255) and nullable.
I am trying to create a constraint that will not allow a row to be entered
if approved is set to false and comments is null.
CHECK constraints work on positives, so restate your condition that
way. A row is permissible if approved is true or the comments are not
null, correct? So...
...add constraint chk_comments (approved or comments is not null)...
This does not work. yada, yada, yada... add constraint "chk_comments' check
(approved = false and comments is not null). The constraint is successfully
added, but does not work as I expected.
That's not the same check as what you described.
An additional comment, did you put the check constraint on a column or
the table?
From the docs:
http://www.postgresql.org/docs/9.2/interactive/sql-createtable.html:
.. A check constraint specified as a column constraint should reference
that column's value only, while an expression appearing in a table
constraint can reference multiple columns...
--
Adrian Klaver
adrian.kla...@gmail.com
--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
