Can there be 3 primary keys?

Can primary key have 3 columns?

As already stated you can have a single primary key which consists of multiple columns if this was your question. If the question was how to make the columns primary keys separately, that's not possible. However, you can create 1 primary key and add two unique keys.

Can you have multiple primary keys?

A primary key is a field or set of fields with values that are unique throughout a table. Values of the key can be used to refer to entire records, because each record has a different value for the key. Each table can only have one primary key.

How many primary keys can we have?

Primary keys must contain UNIQUE values, and cannot contain NULL values. A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).

How many primary keys can be there for a base table?

There are two types of keys: primary and secondary. A primary key uniquely identifies each record in a table. Every table has a primary key, and there can only be one primary key per table.