Why can't I connect to the MYSQL database?

Question

Following the php toolbox, it shows that the database is connected, but it cannot connect to the MYSQL database.

The call displays "Execution failed, please refer to: No database selected"

Answer 1

Don’t forget to add database $dbname when using mysqli_connect(), or use mysqli_select_db() to select a database. Otherwise, you cannot connect to a specific database.

Answer 2

No database selected, which means no database is selected, select it and then import it