Re: Re: DB porting questions...

On Tue, Apr 17, 2001 at 11:45:08AM -0400, Vivek Khera wrote:
> I'm just starting, but I've got two questions.  I've found some
> scripts out there that claim to do the conversion of the SQL create
> commands, but none does the right thing it seems.
Please help better these scripts then. That way you're helping
everybody, including yourself (with gained experience).
> I've now found out how to handle the timestamp for insert times and
> how to do auto-increment fields.
> My unsderstanding of MySQL's enum type is to use something like this
> in postgres:
> 
>  owner_status varchar(9) check 
>         (owner_status in ('pending','active','suspended'))
>         NOT NULL default 'pending',
That's standard SQL, which PostgreSQL supports. You could use this
same statement in Oracle, or other compliant DBs.
> Currently in MySQL I have this:
> 
>  owner_features set('premium','haveccinfo') default NULL,
> 
> for example.  Some other fiels may have about 20 such values, and
> MySQL lets me keep these in 3 bytes as a bit-field behind the scenes.
MySQL is helping you get into trouble by giving you a non-standard way
to do something for which there's a standard.

> >From what I see, my choice in Postgres is to store this as a
> comma-separated string and let my application work as before.
For columns with more than a couple values, I'd suggest normalizing
your tables. In the "owner_features" case above, you could do something
like:
create table owner_features (    feature_id serial         constraint owner_features_pk primary key,    feature
varchar(30)       constraint owner_features_feature_nn not null);
 
Then your table would just reference owner_features.feature_id. Much
cleaner, especially for tables with lots of cases.

> Does anyone have a script that actually handles properly doing auto
> increments with the SERIAL type, and does the set/enum conversions?
What do you mean by "propely doing auto increments"? What's the
problem you are having?
-Roberto
-- 
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