Re: [INTERFACES] Getting max. value size (libpq++)

On Thu, 1 Jul 1999, Philippe Chaintreuil wrote:

> Okay, maybe I'm just not finding it in the documentation, but is
> there a way to find out the max size of a field? Specifically VARCHAR
> fields. For instance if I have a table created with the SQL code:
>
> CREATE TABLE temp_table
> ( name VARCHAR(30),
> id VARCHAR(10),
> address VARCHAR(60));
>
> Now the program I'm writing will add whatever the user wants to
> this table, of what ever size. I'm trying to avoid locking the size of
> the HTML input fields. So is there anyway to get those numbers back from
> Postgres? Right now they're hard-coded in, which really sucks. Thanks.

You need to query the system tables to do this.

Something like (I've not tested this, just lifting bits from the jdbc
source):

select a.attname,a.attlen from pg_attribute a,pg_class c
where c.relname like 'temp_table'
and a.attrelid=c.oid
and a.attnum>0
order by a.attnum;

Peter

--
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