Effective interaction between php and MySQL

As i know how to make HTML forms,and have moderate knowledge of PHP and MySQL so its time to try out some data sharing between php and MySQL.

• Establishing a connection
  First of all we have to build a connection between php functions and MySQl and the command to do that is:-
  mysql_connect("Hostname","username","password");
  
  
• Selecting a database
  Once the connection is established an appropriate database is selected and the command for that is:-
  
  mysql_select_db("database_name",connection_variable);
  
  
• Executing the mysql queries
  mysql_queries is executed by the following command:-
  
  mysql_query( mysql_query variable, connection variable);
  

( Meloni , Julie C. 2005," Sams teach yourself PHP,MysQL and Apache all in one", Sams , ed:2.)