Composite Primary Key

[Gaurav Sharma]

Hi ALL,

Can anybody tell me the significance of Composite Primary key , i created a table with composite primary key with the following structure

"primary key(id,email,name)"

When i am trying to insert the row in the table it is allowing to insert null or empty or even duplicate values in the name and email filed.

So please help me to understand the concept of composite primary key.

Any help or suggestion would be greatly appreciated.

Thanks
Gaurav