Re: [PATCHES] Patch for broken JDBC's getColumn() - Mailing list pgsql-jdbc

From Bruce Momjian
Subject Re: [PATCHES] Patch for broken JDBC's getColumn()
Date
Msg-id 200108302257.f7UMvQi10579@candle.pha.pa.us
Whole thread Raw
In response to Patch for broken JDBC's getColumn()  (Jeroen van Vianen <jeroen@vanvianen.nl>)
Responses Read transactions don't work on 7.0.x db's
List pgsql-jdbc
Your patch has been added to the PostgreSQL unapplied patches list at:

    http://candle.pha.pa.us/cgi-bin/pgpatches

I will try to apply it within the next 48 hours.

> Hi,
>
> Attached is a patch for JDBC's getColumn() function that was broken /
> flawed in the following ways:
>
> 1. Only returned columns that had a default value defined, rather than all
> columns in a table
> 2. Used 2 * N + 1 queries to find out attributes, comments and typenames
> for N columns.
>
> By using some outer join syntax it is possible to retrieve all necessary
> information in just one SQL statement. This means this version is only
> suitable for PostgreSQL >= 7.1. Don't know whether that's a problem.
>
> I've tested this function with current sources and 7.1.3 and patched both
> jdbc1 and jdbc2. I haven't compiled nor tested the jdbc1 version though, as
> I have no JDK 1.1 available.
>
> Note the discussion in http://fts.postgresql.org/db/mw/msg.html?mid=1029626
> regarding differences in obtaining comments on database object in 7.1 and
> 7.2. I was unable to use the following syntax (or similar ones):
>
> select
>      ...,
>      description
> from
>      ...
>      left outer join col_description(a.attrelid, a.attnum) description
> order by
>      c.relname, a.attnum;
>
> (the error was parse error at or near '(') so I had to paste the actual
> code for the col_description function into the left outer join. Maybe
> someone who is more knowledgable about outer joins might provide me with a
> better SQL statement.
>
> Please review.
>
> Regards,
>
>
> Jeroen

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