[newbie] 4 questions about MySql5 here

Hey

I'm trying to write my first stored procedure in MySql5 (I have some
experience with MS Sql Server), but before I begin I have some questions I
would like to have an answer to:

Question 1:
Sql Server has the automatic variable @@error, which if greater than 0 means
the last sql statement failed. What is equivalent at MySql5?

Question 2:
Sql Server has the automatic variable @@row, which tells how many rows was
effected by last sql statement. What is equivalent at MySql5?

Question 3:
A MySql5 stored procedure can have OUT parameter, but it can also have a
RETURN parameter. Is there some guidelines on which to use? Lets says I have
a stored procedure that should send back to my php application the id of the
last inserted primary key in the database.. Should I then use OUT or
RETURN?..

Question 4:
I've read in the MySql5 documentation that mysql_insert_id() returns the
last inserted id. But do this mean the last inserted id in current
transaction or is it the absolute last id (may return the id caused by a
transaction initiated by another user)??? I have to write a stored procedure
which insert a new record into a table and then sends back to my php
application the id of this record...


Jeff

"Jeff" <it_consultant1@hotmail.com.NOSPAM> wrote:

> Sql Server has the automatic variable @@error, which if greater than 0 means
> the last sql statement failed. What is equivalent at MySql5?

No idea. Why do you need this? Declare a handler instead.

> A MySql5 stored procedure can have OUT parameter, but it can also have a
> RETURN parameter. Is there some guidelines on which to use?

If you have only one return value, you should return it with RETURN.
Otherwise you have to use OUT parameters.

> I've read in the MySql5 documentation that mysql_insert_id() returns the
> last inserted id. But do this mean the last inserted id in current
> transaction or is it

There are multiple ways to get the last generated AUTO_INCREMENT value.
mysql_insert_id() is answered by the client itself (using the buffered
result from the last query). LAST_INSERT_ID() is a SQL function that
uses the remembered value from the last AUTO_INCREMENTed column. This
is not the same! Check the manual:

http://dev.mysql.com/doc/refman/5.0/...unique-id.html
http://dev.mysql.com/doc/refman/5.0/...insert-id.html
http://dev.mysql.com/doc/refman/5.0/...increment.html


XL
--
Axel Schwenke, Support Engineer, MySQL AB

Online User Manual: http://dev.mysql.com/doc/refman/5.0/en/
MySQL User Forums: http://forums.mysql.com/