DISTINCT¶

The DISTINCT clause returns only unique (distinct) values from a column or a set of columns, eliminating duplicate rows in the result set.

Syntax¶

SELECT DISTINCT <column_name> [ ,... ]
FROM <table_name>

Parameter	Description
`column_name`	The columns from which to retrieve distinct values
`table_name`	The table from which to retrieve the data

SELECT
  COUNT(DISTINCT department_id)
FROM
  employees;