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phpidiorm

How to check if a tables exists using PDO with Idiorm


/**
 * Check if a table exists in the current database.
 *
 * @param PDO $pdo PDO instance connected to a database.
 * @param string $table Table to search for.
 * @return bool TRUE if table exists, FALSE if no table found.
 */
function tableExists($pdo, $table) {

    // Try a select statement against the table
    // Run it in try/catch in case PDO is in ERRMODE_EXCEPTION.
    try {
        $result = $pdo->query("SELECT 1 FROM $table LIMIT 1");
    } catch (Exception $e) {
        // We got an exception == table not found
        return FALSE;
    }

    // Result is either boolean FALSE (no table found) or PDOStatement Object (table found)
    return $result !== FALSE;
}
  1. How to configure this function with Idiorm PDO?
  2. Is it okey to use -

    try {
        $page = ORM::for_table($table)->where('slug', $slug )->find_one();  
    } (catch $e) {
        // 404 with an error that table does not exists.
    }
    

instead of the "tableExists" function?


Solution

  • If I am understanding your question correctly you want to check if a table exists in a MySQL database.

    Q. 1

    It should be noted that the two queries are not identical. You've got:

    $page = ORM::for_table($table)->where('slug', $slug )->find_one();
    

    But your second query should be:

    $page = ORM::for_table($table)->select_expr(1)->find_one();
    

    See the result columns documentation for information.

    Q. 2

    Yes, Idiorm uses PDO underneath so you'll get the same PDO exception - this is something you really could just try and see how it works with:

    try {
        $page = ORM::for_table($table)->where('slug', $slug )->find_one();  
    } (catch $e) {
        var_dump($e);
    }