如何在php中选择mysql数据库？

Question

I have this code:

               if(!mysql_connect($host,$user,$passwd)){
                    die("Hoops, error! ".mysql_error());
                }

...no error from here.

                if(!mysql_select_db($db,$connect)){
                    $create_db = "CREATE DATABASE {$db}";
                    mysql_query($create_db,$connect);
                    mysql_query("USE DATABASE {$db}",$connect);
                }

..."no database selected" error from here. I would like to select database if it exists and if doesn't then create it and select it.

Why is my code not right?

Thank you in advance

Answer 1

Where are you saving the value returned by mysql_connect()? Don't see it here. I assume $host, $user, $password and $db are properly set ahead of time. But you're passing a param to mysql_select_db that may not be properly set.

$connect = mysql_connect($host,$user,$passwd);
if (!$connect) {
    die('Could not connect: ' . mysql_error());
}
if(!mysql_select_db($db,$connect)) ...

Start by checking to see if you can select without the CREATE query first. Try a simple SELECT query to start. If you can connect, select the db, and execute a SELECT query, that's one step. Then try the CREATE query. If that doesn't work, it's almost certainly a matter of permissions.