Question

We all know that it’s better to use multiple inserts in ONE query than to run MULTIPLE queries. But, I don’t know upto how many these multiple extended values does Mysql support? I searched over net but didn’t find the correct answer. I’m just curious to know this.

Example,

INSERT INTO tbl_name VALUES(1, 'John Doe'), (2, 'Peter England'), ....

I remember when I was using some MVC framework where it was trying to fire hundreds/thousands of inserts in one query, I used to get some sort of error message like Mysql server has gone away.

Answer 1

The limit for multiple inserts, like the one you are talking about would be bound by the packet limit.

See: http://dev.mysql.com/doc/refman/5.1/en/packet-too-large.html

This will affect all query types, and not just insert.

To add a little more context, the error you spoke of MySQL server has gone away would be a result of exceeding the packet limit. A quote from the page:

You can also get these errors if you send a query to the server that
is incorrect or too large. If mysqld receives a packet that is too
large or out of order, it assumes that something has gone wrong with
the client and closes the connection. If you need big queries (for
example, if you are working with big BLOB columns), you can increase
the query limit by setting the server’s max_allowed_packet variable,
which has a default value of 1MB. You may also need to increase the
maximum packet size on the client end. More information on setting the
packet size is given in Section C.5.2.10, “Packet too large”.