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 cwhere c.relname like 'temp_table'    and a.attrelid=c.oid
anda.attnum>0order by a.attnum;
 

Peter

--       Peter T Mount peter@retep.org.uk     Main Homepage: http://www.retep.org.uk
PostgreSQL JDBC Faq: http://www.retep.org.uk/postgresJava PDF Generator: http://www.retep.org.uk/pdf