The DISTINCT clause removes duplicate rows in the result set of a SQLite SELECT statement.
In most simple terms, the syntax is as follows:
SELECT DISTINCT col1, col2 FROM table;
This SELECT statement will only return unique rows. This is due to the use of the DISTINCT clause. Referring to above example this means that only those rows will be returned for which the entries in col1 and col2 combined are unqiue (i.e. not duplicates).