Exercise – Selecting unique first names

Write an SQL statement that selects all the names from the person table without duplicates. For example, assume that there are three records in the person table that have these first names: Jim, Jim, and Bill. The SQL statement you write must return Jim and Bill, without repeating the name Jim twice.

We did not explain how to do it; you have to read the SQL documentation to find out how to select unique values.

Answer

Use the distinct keyword. The following SQL statement returns unique first names:

select distinct first_name from person;