Question

I wish to create a MySQL table using PHP and PDO. I also wish to parameterize the table name. I have already attempted to implement this and the code, with errors, is shown below.

class databaseaccess {

    public $hostname = 'localhost';
    public $username = 'root';
    public $password = 'root';
    private $db = null;
    public $rows;

    public function __construct() {
        try {
                $this->db = new PDO("mysql:host=$hostname;dbname=noteshareproject", $this->username, $this->password);
        }
        catch (PDOException $Exception) {
            throw new Exception("DB failed to connect ".$Exception->getMessage());
        }
    }

    public function writetable($title,$id){
        if ($this->db === null) throw new Exception("DB is not connected");
        //query works with `:title` however keeps the commas. Gotta find out what is wrong.
        $query = "CREATE TABLE noteshareproject.:title (id INT NOT NULL AUTO_INCREMENT, PRIMARY KEY(id), username VARCHAR(20)) ENGINE=myISAM;";
        $statement = $this->db->prepare($query);
        $title = $title . $id;
        $title = (string) $title;
        $statement->bindValue(':title', $title, PDO::PARAM_STR);
        $statement->execute();
        print_r($statement->errorInfo());
        echo $title;

    }
}

The output of the above code is as follows:

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 ''exampletablename'(id INT NOT NULL AUTO_INCREMENT, PRIMARY KEY(id), username VARCHAR(20)) EN' at line >2
)
exampletablename

What have I done wrong in my MySQL syntax or PDO implementation?

Answer 1

You cannot use placeholders in prepared statements for identifiers (column/table/database/function names etc). You can only use them for values.

CREATE TABLE noteshareproject.:title
//                            ^^^^^^ this will not work

You will have to manually sanitise $title so it can be used directly in the string if you want to do this.

Note also that a DDL statement such as CREATE TABLE cannot be prepared, so there is no point in using prepare(). You might as well just use query() or exec().

I do also wonder if the fact that you want to do this at all is an indicator of poor database design – it is unlikely that a requirement for multiple tables of identical structure is a proper way to store your information, although without knowing more about your application it is impossible to say for sure.