Why doesn't joining multiple MySQL queries with semicolons work with Perl DBI?

问题

I would like to insert values into two separate MySQL tables using DBI. I tried to combine two working INSERT queries into one by inserting a ; between them:

$dbh->do(q{
    INSERT INTO `testA`(test) values('testvalue111');
    INSERT INTO `testB`(test) values('testvalue222');
});

But I always get an error:

Syntactic error in "INSERT INTO `testB`(test) values('testvalue222 ..."

If I separate the queries into two separate do calls, it works. But the combined query works fine in phpMyAdmin. Why does it fail in Perl?

回答1:

You need to set an option in the connect call to enable this. From the docs:

mysql_multi_statements
As of MySQL 4.1, support for multiple statements seperated by a semicolon (;) may be enabled by using this option. Enabling this option may cause problems if server-side prepared statements are also enabled.

It is disabled by default, and should probably remain unset - that's a large avenue for SQL injection (which you should be reading about especially if you're not using binds).

回答2:

By default, DBD::mysql doesn't allow you to execute multiple statements at once. Although you can enable this with the mysql_multi_statements option as Mat showed, you shouldn't do that: among other things, your code will be less portable because some database drivers don't have any such option, and it can cause issues with prepared statements.

Instead, just issue a separate DBI command for each statement.

回答3:

INSERT INTO testA(test) values('testvalue111'),('testvalue222');

来源：https://stackoverflow.com/questions/13333230/why-doesnt-joining-multiple-mysql-queries-with-semicolons-work-with-perl-dbi