Re: Joins in ORACLE

"Chris" <CHRISVAL_at_bigpond.com.au> wrote in message news:cdJv6.3741$45.18331_at_newsfeeds.bigpond.com...
> "Steve Bell" <swayne.bell_at_sympatico.ca> wrote in message
> news:3ABF5748.3047AC70_at_sympatico.ca...
> : Hi Chris,
> :
> : The very short answer to this.......
> : In a normailized relational database there is often the
 requirement to
> : SELECT information from more than one table at a time to
 get meaningful
> : results (for example, if EMPLOYEE is a child table of
 DEPARTMENT you may
> : simultaneously need to select columns from both tables to
 determine the
> : name of the department corresponding to each employee).
> : To do this you include in your WHERE clause a condition
 similar in form
> : to:
> : where childtable.foreignkey = parenttable.primarykey
> :
> : This syntax, known as an equijoin, will only return rows
 where a record
> : exists in both tables.
> : There are other kinds of joins, but this is the first you
 will
> : encounter.
> :
> : If you're interested you can pick up almost any book on
 SQL and it
> : should give you examples of the different kinds. Try to
 find one that
> : uses the syntax that Oracle uses; they'll usually say.
> :
> : Hope this can get you started,
> : Steve
> :
> : Chris wrote:
> :
> : > Hi everyone, I'm at school currently learning Oracle
> : > as one of my subjects. I recently heard a few people
> : > speaking about Joins and since I will be covering them
> : > next term, I'd like to get a head start on understanding
> : > them. My question is, can someone please explain the
> : > concept of joins or point me in the right direction, or
 even
> : > a small sample piece of code would be great.
> : >
> : > Any help appreciated.
> : >
> : > Thank You
> : > Chris Val
>
>
> Thanks for your help Steve, it looks pretty simple after
> all.
> now I can look into it further with some confidence.
> BTW::) I am looking to buy a good book on oracle very soon
> as the ones we are provided with at school are, well lets
> just
> say they are very slim (20 Pages in fact LOL)...
>
> Thanks again Steve.
>
> Chris Val
>
>

Buy the book on SQL by Rick van der Lans. It originally appeared in Dutch in 1986 and has been translated into English many years ago. Amazon sells it.

Hth,

Sybrand Bakker, Oracle DBA Received on Mon Mar 26 2001 - 10:57:05 CST