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
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.
You might need database create permissions for the user attempting to create the database. Then you need to operate on a valid connection resource. $connect never looks to be assigned to the connection resource.
You should check the return value of mysql_query() - currently if any of those calls fail you won't know about it:
if(!mysql_select_db($db,$connect)){
if (!mysql_query("CREATE DATABASE $db", $connect)) {
die(mysql_error());
}
if (!mysql_select_db($db, $connect)) {
die(mysql_error());
}
}
Why not simply use the CREATE DATABASE IF NOT EXISTS syntax instead?
Something like this ...
$con = mysql_connect('localhost');
$sql = 'CREATE DATABASE IF NOT EXISTS {$db}';
if (mysql_query($sql, $con)) {
print("success.
");
} else {
print("Database {$db} creation failed.
");
}
if(!mysql_select_db($db,$connect)){
print("Database selection failed.
");
}
Change the line
mysql_query($create_db,$connect);
mysql_query("USE DATABASE {$db}",$connect);
To
mysql_query($create_db,$connect);
mysql_select_db($db);*
and it should work.
you could try w3schools website. They have a very simple and easy to learn tutorial for selecting database. The link is : http://www.w3schools.com/php/php_mysql_select.asp Hope this help :)
I would like to thank to all of you, however I found fault on my side. This script was in class and one of variables were not defined inside this class. So I'm really sorry. I don't know how to consider the right answer, but I noticed my mistake after reading Clayton's answer about not properly set parameters, so I guess he is the winner ;)