I have an existing table called Persion. In this table I have 5 columns:
- persionId
- Pname
- PMid
- Pdescription
- Pamt
When I created this table, I set PersionId and Pname as the primary key.
I now want to include one more column in the primary key – PMID. How can I write an ALTER statement to do this? (I already have 1000 records in the table)