Styjun

I m running PHP 7.2.16

Not sure when started, PDO errorCode() or errorInfo()[0] now always shows 00000 even there is an error

$pdo = new PDO('mysql:host=localhost;dbname=mydb', 'root', 'pwd');
$sth = $pdo->prepare('select now() and this is a bad SQL where a - b from c');
$sth->execute();
$row = $sth->fetchAll();
$err = $sth->errorInfo();
echo $sth->errorCode();
print_r($row);
print_r($err);

And here is the result:

00000Array
(
)
Array
(
 [0] => 00000
 [1] => 1064
 [2] => You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'a bad SQL where a - b from c' at line 1
)

However, I just did a new test, by delete $sth->fetchAll() or get error before this line, it shows correctly:

Array
(
 [0] => 42000
 [1] => 1064
 [2] => You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'a bad SQL where a - b from c' at line 1
)

OK - the solution is that:

get the error code immediately after execute() and before any fetch

I tested this code with PHP 7.1.23:

$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
$sth = $pdo->prepare('select now() and this is a bad SQL where a - b from c');
if ($sth === false) 
 echo "error on prepare()n";
 print_r($pdo->errorInfo());

if ($sth->execute() === false) 
 echo "error on execute()n";
 print_r($sth->errorInfo());

Output:

error on execute()
Array
(
 [0] => 42000
 [1] => 1064
 [2] => 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 'a bad SQL where a - b from c' at line 1
)

Then I tested the same code, except after disabling emulated prepare:

$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

Output:

error on prepare()
Array
(
 [0] => 42000
 [1] => 1064
 [2] => 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 'a bad SQL where a - b from c' at line 1
)

Fatal error: Uncaught Error: Call to a member function execute() on boolean

Moral of the story:

• When using emulated prepared statements, prepare() is a no-op, and the error is delayed until execute(). I recommend disabling emulated prepare, unless you use a database that doesn't support prepared statements (I don't know of any current version of any RDBMS product that can't do real prepared statements).




• When checking for an error on prepare(), use $pdo->errorInfo().




• When checking for an error on execute(), use $stmt->errorInfo().