Hai everyone, i have two tables Center and Batch.

The fields are,

Center:
Center_id,Centername

Batch:
Batch_id,Batchtiming,Center_id

The two tables are related by Center_id. In the center table Center_id is the primary key and in Batch table Batch_id is the primary key. I want to combine in Batch_id and Center_id in Batch table since i have multiple entries of Batch_id in the Batch table, which is not allowed when i have only Batch_id as primary key.

Please help me out. Thank you,