Error when preparing a multiple insert query

There are a few things that could cause an error when preparing a multiple insert query in PHP. Here are some possible issues you might encounter and some things you can try to fix them:

1. Syntax error in the query: Make sure that your query is correctly formatted and that you are using the correct syntax for multiple insert queries.
2. Incorrect number of placeholders: Make sure that you have the correct number of placeholders (i.e., ?) in your query. Each placeholder should correspond to a value that you are inserting.
3. Incorrect data types for placeholders: Make sure that the data types of the values you are binding to the placeholders match the data types expected by the database.
4. Manual escaping: Prepared statements handle special characters automatically. Do not manually escape values (e.g., ', ", \) before binding them, as this contradicts the core purpose of prepared statements and can cause binding errors.

To execute a multiple insert query in PDO, pass an array of arrays to execute():

$sql = "INSERT INTO users (name, email) VALUES (?, ?), (?, ?), (?, ?)";
$stmt = $pdo->prepare($sql);
$stmt->execute([
    ['Alice', '[email protected]'],
    ['Bob', '[email protected]'],
    ['Charlie', '[email protected]']
]);

If you continue to have issues, debug by checking PDO error modes (PDO::ERRMODE_EXCEPTION), logging $stmt->errorInfo(), or verifying your data array structure. You can also test the base query directly in your database client to isolate syntax issues.