Re: Re: Is there any easy way to determine a default value specified for table column? - Mailing list pgsql-general

From Tom Lane
Subject Re: Re: Is there any easy way to determine a default value specified for table column?
Date
Msg-id 24027.1268594616@sss.pgh.pa.us
Whole thread Raw
In response to Re: Is there any easy way to determine a default value specified for table column?  (Thomas Kellerer <spam_eater@gmx.net>)
List pgsql-general
Thomas Kellerer <spam_eater@gmx.net> writes:
> Belka Lambda wrote on 14.03.2010 01:24:
>> Is there a way to "nicely" determine a default value of a table column? A function, which could be used, like:

> The defaults are store in pg_attrdef, the corresponding column definitions in pg_attribute.

> So you would need to do a join between the two tables, something like:

> select c.relname, a.attname, def.adsrc
> from pg_attrdef def
>    join pg_class c on def.adrelid = c.oid
>    join pg_attribute a on a.attrelid = c.oid and a.attnum = def.adnum
> where c.relname = 'the_table_name'

Relying on adsrc is a very bad idea.  I'd suggest
    pg_catalog.pg_get_expr(adbin, adrelid)
which is what pg_dump uses.

            regards, tom lane

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