How Can I Effectively Handle Query Errors When Using PDO prepare() in PHP?

Retrieving Query Errors from PDO prepare() in PHP

When using the prepare() method in PDO PHP to prepare a database query, it's essential to handle potential errors. The original example cited in the question failed to handle query errors effectively.

To correctly check for query errors, follow these steps:

1. Configure PDO Error Handling:

Set the PDO error handling mode to PDO::ERRMODE_EXCEPTION using the setAttribute() method:

$st = $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

This instructs PDO to throw exceptions for database errors, making it easier to identify and handle them.

2. Disable Emulation:

Disable the PDO::ATTR_EMULATE_PREPARES feature by setting its value to false:

$st = $db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

This disables a PHP emulation layer, ensuring that the MySQL server parses queries immediately after the call to prepare().

3. Catch Exceptions:

Since the prepare() method is now throwing exceptions for errors, use "try-catch" blocks to handle them:

try {
    $st = $db->prepare('INSERT INTO DoesNotExist (x) VALUES (?)');
} catch (PDOException $e) {
    echo "Error: " . $e->getMessage();
}

This code will output the following error message when the non-existent table DoesNotExist is referenced:

SQLSTATE[42S02]: Base table or view not found: 
1146 Table 'test.doesnotexist' doesn't exist

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