On Wed, 2003-09-03 at 09:50, Vivek Khera wrote:
> >>>>> "SD" == Shridhar Daithankar <shridhar_daithankar@persistent.co.in> writes:
>
> SD> On 3 Sep 2003 at 14:30, Bruno BAGUETTE wrote:
> >> The problem is that this MySQL database uses ENUM, do you see what can I
> >> do to migrate ENUM into PostgreSQL ?
>
> SD> varchar with check constraints. Add constraits to allow only
> SD> certain values of varchar string.
>
> I used to do this. It turns out to be horribly inflexible when you
> need to alter the enum values since the constraints cannot easily be
> changed.
It'll be better when domains have alterable constraints. Your
way is the traditional (and best, IMO) way, though.
> What I do is create a short table for the enum like this:
>
> CREATE TABLE status_levels (
> status varchar(10) PRIMARY KEY
> ) WITHOUT OIDS;
> INSERT INTO status_levels (status) VALUES ('active');
> INSERT INTO status_levels (status) VALUES ('overdue');
> INSERT INTO status_levels (status) VALUES ('suspended');
> INSERT INTO status_levels (status) VALUES ('terminated');
>
> then reference it via foreign key from the "enum" field:
>
> CREATE TABLE whatever (
> ...
> status varchar(10) NOT NULL DEFAULT 'active' REFERENCES status_levels(status),
> ...
> );
>
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Ron Johnson, Jr. ron.l.johnson@cox.net
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