blackdevil

HI all. I am currently designing MysQL database and facing few problem about queries. Here it goes. I have 2 table: table 1 (consists of 2 fields:Student Metric and Course Id) and table 2 (consists of 4 fields: Student Metric, Class Id, Date, Time). Now I need to list a query between the 2 tables that lists the Student metric fields which contained in table 1 but not contained in the table 2. How can I do that in PHP code communicating with MySQL database? Thanks for any help in advance.. Cheers