Locking a MySQL database so only one person at once can run a query?

Question

I am having a few issues when people are trying to access a MySQL database and they are trying to update tables with the same information.

I have a webpage written u

Answer 1

You're looking for LOCK.

http://dev.mysql.com/doc/refman/5.0/en/lock-tables.html

This can be run as a simple mysql_query (or MySQLi::query/prepare).

I'd say it's better to lock specific tables (although you can probably try LOCK TABLES *) that need to be locked rather than the whole database - as nothing will be able to be read. I think you're looking for something like:

LOCK TABLES items;
START TRANSACTION;
INSERT INTO items (name, label) VALUES ('foo', 'bar');
UNLOCK TABLES;

Or in PHP:

mysql_query('LOCK TABLES items');
mysql_query("INSERT INTO items (name, label) VALUES ('foo', 'bar')");
mysql_query('UNLOCK TABLES');