Yes, @Ron reply makes sense you can use a CHECK constraint or FOREIGN KEY.
On Tue, Feb 26, 2019 at 8:54 PM Ron <ronljohnsonjr@xxxxxxxxx> wrote:
On 2/26/19 9:11 AM, Campbell, Lance wrote:
PostgreSQL 10.x
What is the best way to restrict the values on a text field to make sure they only contain particular values: Example: The field “type” can only contain the values of “X”, “Y” and “Z”. Would a trigger be the best strategy? Or is there a special SQL type I should use in this particular case?
Use either a CHECK constraint or FOREIGN KEY.
For just a few items, understanding that you must drop and recreate the constraint to modify it. http://www.postgresqltutorial.com/postgresql-check-constraint/
CREATE TABLE foo
(
bar VARCHAR(20) CHECK (bar IN ('X', 'Y', 'Z'))
);
For more items, and simpler additions: http://www.postgresqltutorial.com/postgresql-foreign-key/
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