Concurrent Access to MySQL tables

ldd76

Hi all,

I am quite a novice in MYSQL. I have setup a leave management system which allows users in my company to access. I need to do something which allows users to concurrently update, insert or delete to the data in the database while still mainiaining data integrity.

How can this be done? A sample code will be good enough Thanks...

bastien

what front end are you planning to use ?

php and browser...then its simple

if (!$_POST['submit']){

show_form();

}esle{

update_data();

}

function show_form()
{

//php and html code to create the form

}

function update_data()
{

//here goes the php to get the data and place it in the db
//this can be done inline (with the db connection in the page)
//or using an include("connection.php");  which stores all the
//connection strings and passwords in a file that gets included 
//in the script

//[b]you decide which one you are gonna use
//there are plenty of examples here-->search for them
//i know i've left lots

[/b]
}

chriskl

It's MySQL dude - if you care about your data integrity, don't use it.

The best you can do is this:

Make all your tabels InnoDB so you can use transactions, row locking and foreign keys.
If you read from a row and update it based on what your read, you MUST do it in a transaction using a row lock:

BEGIN;
SELECT val FROM table WHERE blah FOR UPDATE;
UPDATE table SET val='1' WHER blah;
COMMIT;

You must use foreign keys to relate your data properly. MySQL doesn't have cascade options on its FKey's, so that's a huge pain in the butt. Also, I belive they don't dump and restore properly.

Chris