Can primary key have 3 columns?

Can we have 3 columns as primary key?

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.

How many columns can a primary key have?

In both these examples, primary key contains only one column.

Can you have multiple columns as primary key?

A table can have only one PRIMARY KEY either on one column or multiple columns. When multiple columns are defined as PRIMARY KEY, then, it is called COMPOSITE KEY.

Is primary key only one column?

You can have only one primary key in a table, but it can consist of multiple columns. This doesn't mean that each column is a primary key, but that the combination of all these columns' values are unique.