Re: Which column is taken in JOIN with multiple columns and different content ?

Tobias Merler wrote:
> Assume I join two tables.
> Both of these tables contain a column with name "col1". This column ist not he primary key.
> However this column contains different values which value is taken ?
>
> Lets see the following example:
>
> Select *
> FROM tablea a, tableb b
> Where a.id = b.id
>
> tablea:
>
> id col1 col2
>
> 1 aaa ddd
> 2 bbb eee
> 3 ccc fff
>
>
> tableb:
>
> id col1 col3
>
> 1 zzz uuu
> 2 xxx vvv
> 3 yyy www
>
> The result table will look like:
>
> id col1 col2 col3
>
> 1 ??? ddd uuu
> 2 ??? eee vvv
> 3 ??? fff www
>
> Which values will be for the questions marks ?
>
> Ok, I know the data model is not perfect and the two tables could be merged.
> But keep in mind that the sample is only a simplified version of a more complex
> SQL statement. So lets concentrate on my question.
>
> Thank you
>
> Toby

Based on your SELECT statement (SELECT *) all of them.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org