Can PDO Parameters Be Used for Table or Column Names in SQL Queries?

PDO Parameters: Can They Accept Table or Column Names as Input?

Attempting to include the table name as a parameter in a PDO prepared statement, as illustrated in the code snippet below, will result in failure:

$stmt = $dbh->prepare('SELECT * FROM :table WHERE 1');
if ($stmt->execute(array(':table' => 'users'))) {
    var_dump($stmt->fetchAll());
}

Why is This Not Possible?

PDO parameters are intended for data values that are dynamically assigned during query execution. Table and column names, on the other hand, are static elements of the database schema and not suitable for parameterization.

Safe Alternative for Including Table Names

To safely insert a table name into an SQL query, it is recommended to manually filter and sanitize the data. This can be achieved by incorporating a white-listed switch() statement into the function that executes the query dynamically:

function buildQuery( $get_var )
{
    switch($get_var)
    {
        case 1:
            $tbl = 'users';
            break;
    }

    $sql = "SELECT * FROM $tbl";
}

By setting up specific cases and handling any invalid scenarios, the query will only execute with allowed table names. This approach ensures that user input does not directly influence the SQL query, preserving data integrity.

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