Comments on: SQL tutorial?

By: ds1

ds1 — Thu, 28 Apr 2011 07:25:46 +0000

Here is a good reference on SQL Tutorial. Thousands of queries maintain SQL 2003 standard.

By: kccrosser

kccrosser — Wed, 29 Sep 2010 18:29:34 +0000

Generally (but not always):
A Function can take formal input parameters, and cannot modify the parameters – instead the function returns one result parameter that is not in the formal parameter list. Further, normally a Function is prohibited from having “side effects” – i.e., a Function cannot alter the state of the system, change data in a table, etc.
A Procedure can take input, output, and/or input/output parameters and can modify the contents of the parameters directly. Also, a Procedure is usually NOT prohibited from having “side effects” – it can modify the state of the system, change table contents, etc.

Example:

declare @a int;
declare @b varchar(256);
declare @c float;
exec MyProcedure @a out, @b out;
--  at this point, either or both of @a and @b can have different values than before the procedure call
--  also, database tables could have been modified (or even created/dropped!)
set @c = MyFunction(@a, @b);
--  at this point, neither @a nor @b can be modified by MyFunction, but a result value is returned - nothing in the database should have been altered as a result of this call
--  note that the following IS allowed, and is how you would use a function to modify the value of an argument:
set @a = MyFunction(@a);

By: radhakrishnatutika

radhakrishnatutika — Wed, 29 Sep 2010 04:37:43 +0000

what is the diff bw procedure and function?

By: tomatoes

tomatoes — Wed, 30 Jun 2010 07:08:48 +0000

This SQL tutorial offers examples for each command so it's easy to learn along.

By: brentsheets

brentsheets — Mon, 06 Apr 2009 13:46:32 +0000

Moderator Note: Lystra, as Carlosdl pointed out - as you run into specific issues - please feel free to return and post a questions with as much detail, as possible. Good luck here is another online tutorial you may wish to visit at SQLCourse dot com. And you may also wish to visit the SQL and SQL Server Tutorial and Reference Guide that has been created from content from fellow member and SQL guru Denny Cherry. Denny has a blog on IT Knowledge Exchange called SQL Server with Mr. Denny.

By: carlosdl

carlosdl — Mon, 06 Apr 2009 03:15:42 +0000

If yoou have some specific questions, feel free to post them here.