Re: Querying the schema for column widths - what syntax do I use?

Richard Huxton wrote:

Howard Wilkinson wrote:

I am working on some upgrades to the MyDNS open source product. I have some expertise in MySQL but am not overly familiar with PostgreSQL and need some guidance on how to query the schema for the maximum size of data a column can hold.

Unless you're after PG-specific stuff, it's probably best to use the information-schema.

http://www.postgresql.org/docs/8.3/static/information-schema.html

This has a standard layout cross-database, so will help you to extend you app across other systems. I think it's supported in the latest version of MySQL too.

SO I can do something like this?

select character_maximum_length from information_schema.columns where table_name='rr' and column_name='data';

Yes?