RE: select on multiple tables

Unfortunately id doesn't return A.c and B.c. Try it in psql...

One way to solve this is to fix the backend to return fully qualified
column names.

Dave

-----Original Message-----
From: pgsql-jdbc-owner@postgresql.org
[mailto:pgsql-jdbc-owner@postgresql.org] On Behalf Of Rene Pijlman
Sent: August 20, 2001 3:49 PM
To: Carterette, Ben
Cc: 'pgsql-jdbc@postgresql.org'
Subject: Re: [JDBC] select on multiple tables


On Mon, 20 Aug 2001 12:50:22 -0500, you wrote:
>The SELECT is in a servlet, something like this:
>
>rs = stmt.executeQuery("SELECT * FROM " +
>request.getParameter("table1") + ", " +
>request.getParameter("table2")); session.setAttribute("result", rs);
>request.sendRedirect(request.getParameter("page2"));
>
>that's a simplification of what it does, but it's good enough for
>demonstration I think.
>
>The .jsp file that calls the servlet knows what tables it wants to read

>out of, and the .jsp file that the servlet redirects to knows what
>columns it wants.  The servlet doesn't know anything and hopefully
>shouldn't care.  I wanted to abstract it as much as possible.

How about using ResultSetMetaData.getColumnName() on the ResultSet to
dynamically query the column names? See:
http://java.sun.com/j2se/1.3/docs/api/java/sql/ResultSetMetaData.html

I don't know that this will (and should) return when you do SELECT *
from A, B and there is a column c in both tables. Hopefully it returns
A.c and B.c.

Regards,
René Pijlman

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