Re: distinguishing identical columns after joins

In times like these, I usually write a query using
information_schema.columns to generate the column list:

SELECT ordinal_position,
1 AS table_instance,
'a.' || column_name || ' AS ' || column_name || '_a,'
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'your_table_here'
UNION ALL
SELECT ordinal_position,
2 AS table_instance,
'b.' || column_name || ' AS ' || column_name || '_b,'
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'your_table_here'
ORDER BY table_instance,
ordinal_position;

Or something along those lines, and copy-and-paste the results into the
query. It's quicker than typing them all out once you hit a certain
number of columns, and certainly less typo-prone.

It's not the shortcut you were thinking of but it works.

On 3/1/2011 5:13 PM, S G wrote:
> Rob, what you wrote certainly does work. But suppose you had to do
> that for a join with 50 columns in each table, and you really needed
> to see all those columns show up in the final result set, and
> furthermore, you needed to be able to identify each one uniquely in
> the final result set. Explicit renaming works, but it's tedious.
> Call me lazy. I'm hoping a column-renaming shortcut exists that works
> with the "SELECT *" concept.