Originally Posted by Billingsley

Thank you. This is valuable. So, if rownum= 1 is returning only the top row for each job_Id, what would happen if I used subqueries for all the columns in the SELECT statement, with no distinct? Actually, I did that. I can see that it only returns the first JOb_ID but it returns 12 of them, and there aren't 12 in the database with that Id. In fact, there is only one. What is happening?

Also, I'm new to this community. I noticed something about clicking a link to promote you or give you points or something. I can't remember. I certainly intend to do that, but what does it mean?

Many thanks,
Lewis

Originally Posted by cgyrob

By only doing subqueries you basically created a cartesian join. It displayed a record for every possible permutation of the query.

There is a simple explantion of cartesian (cross joins) here.

http://www.dba-oracle.com/t_garmany_...cross_join.htm

As for the community. It is expected when a question you ask is solved you set the thread to solved.

Reputation points can be given as well by clicking on the link below the user name. I beleive your reputation altering power is determined by your own reputation and number of threads participated in as well as solved, possibly the reason it is encouraged to mark threads solved when complete as well as keeping the site clean.

You can see what you reputation altering power is by looking in your account by clicking on your own link.

Have a good one.