Multiple Updates in MySQL

Question

I know that you can insert multiple rows at once, is there a way to update multiple rows at once (as in, in one query) in MySQL?

Edit: For example I have the followi

Answer 1

Why does no one mention multiple statements in one query?

In php, you use multi_query method of mysqli instance.

From the php manual

MySQL optionally allows having multiple statements in one statement string. Sending multiple statements at once reduces client-server round trips but requires special handling.

Here is the result comparing to other 3 methods in update 30,000 raw. Code can be found here which is based on answer from @Dakusan

Transaction: 5.5194580554962
Insert: 0.20669293403625
Case: 16.474853992462
Multi: 0.0412278175354

As you can see, multiple statements query is more efficient than the highest answer.

If you get error message like this:

PHP Warning:  Error while sending SET_OPTION packet

You may need to increase the max_allowed_packet in mysql config file which in my machine is /etc/mysql/my.cnf and then restart mysqld.