It can be solved by mysqli connect.
Mysqli_array() has two parameters. The first is the name of the connection mysql.
The main problem is that brackets  in the database need to be quoted.
Such an error as fatal error was encountered: Uncaught Error: Call to undefined function mysql_connect()
Resolved as follows：
1. MySQL is not connected properly
2. if MySQL is normal or the connection is wrong, replace MySQL connect () with mysqli connect ()