Import from mysqldump not working as expected - php

Question

I've got an sql dump generated from mysqldump. This file includes mysql-version specific comments (/*!{MySQL version number} {Code} */).
If I insert an sql syntax error after this block, PDO doesn't trigger an exception.
php code
$sql = file_get_contents('FooBar.sql');
$pdo = new \PDO('mysql:host=localhost;dbname=FooBar', 'root');
$pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
$pdo->exec($sql);
FooBar.sql
/*!40101 SET #Foo='Bar' */;
ERROR
INSERT INTO Foo VALUES ('Bar');
This executes without causing any exceptions or errors. If I either remove the /*!40101 SET #Foo='Bar' */; statement, or move the error on line up an PDOException is thrown.

Answer 1

Thanks to the hek2mgl's for putting me on the right path.
PDO doesn't support multiple queries. If you execute a statement containing multiple queries, they get executed, but it seems PDO stops behaving after the first query is executed. The /*!{MySQL version number} {Code} */ style comment gets executed as a regular query by MySql and anything after this gets ignored by PDO, even though it gets executed by MySql.
The same error indicated would trigger by the following query:
SET #Foo='Bar';
ERROR
INSERT INTO Foo VALUES ('Bar');
To make this work using PDO, I need to split up the statements.
$sql = file_get_contents('FooBar.sql');
$lines = explode(';', $sql);
$pdo = new \PDO('mysql:host=localhost;dbname=FooBar', 'root');
$pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
foreach ($lines as $line) {
$trimmedLine = trim($line, " \t\n\r\0\x0B");
if (strlen($trimmedLine) > 0) {
$pdo->exec($trimmedLine.';');
}
}
EDIT:
An alternative solution is to use pdo prepared statements.
$sql = file_get_contents('FooBar.sql');
$pdo = new \PDO('mysql:host=localhost;dbname=FooBar', 'root');
$stmt = $pdo->prepare($sql);
$stmt->execute();
do {
... Do stuff ...
} while ($stmt->nextRowset());
if ($stmt->errorCode() != '00000') {
... Handle error ...
}

Answer 2

It's because of the ; at the end of the comment. I don't know why at the moment. Will investigate further...
Found this bug report. But don't expect the char encoding to be a problem as I've investigated the network traffic using wireshark and the MySQL returns a Syntax error (as expected.) Still don't know why PDO doesn't handle this correctly.
A workaround would be to use Mysqli which seems to handle this properly. The following example demonstrates this:
$pdo = new PDO('mysql:host=localhost;dbname=test', 'user', 'secret');
$result = $pdo->query('
SELECT 1 AS num;
ERROR
SELECT 1 AS num;
');
if(!$result) {
var_dump($pdo->errorInfo); // silence ...
}
$mysqli = new Mysqli('localhost', 'root', 'user', 'secret');
$result = $mysqli->query('
SELECT 1 AS num;
ERROR
SELECT 1 AS num;
');
if(!$result) {
print( $mysqli->error);
// Output: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ERROR SELECT 1 AS num' at line 2
}