Does the connection job clear the selected database?

Question

ABOUT,

this is really the bottom line where the question arises. But you may need other information after this, for example, how I connected, etc., to avoid misunderstandings. :)

$con = mysql_connect('localhost', 'root', '******'); if(!$con) { die('Could not establish connection: ' . mysql_error); } mysql_select_db('hunkusersystem'); function user_login($username, $password) { //Avoid SQL-injections. $username = mysql_real_escape_string($username); $password = md5($password); //Match user and password $sql = mysql_query("SELECT * FROM usersystem WHERE username = '$username' AND password = '$password' LIMIT 1", **$con**); 

My question is, in the very last block of code, I cannot use the resource identifier .. Why is this? Is it because mysql_select_db will be "cleaned up"? So, are you standing with the right connection, but without a database? If I used multiple connections, I must define the connection in mysql_select_db ();

Thanks so much for your help :) Greetings from Swe.

Answer 1

This is a coverage issue; user_login cannot see $con because it was not passed as a parameter or declared as a global variable.

(Please do not declare it as a global variable, this is a very bad practice)

Try:

 function user_login($username, $password, $con) { 

Answer 2

The $con variable is defined in the global scope, not in the local scope of the function.

If you want to use it there, you can use:

 function user_login($username, $password) { global $con; 

However, you better pass the variable to the function as a parameter.

The best solution would be to switch to PDO / mysqli with prepared instructions and use dependency injection, but not outside the scope of your question.