sql count unique values in column code example
Example 1: select count of distinct values sql
SELECT COUNT (DISTINCT column-name) FROM table-name
Example 2: count in sql and diff
select (count(city)-count(distinct city)) from station;
Example 3: sql server select rows by distinct column
SELECT a.*
FROM emails a
INNER JOIN
(SELECT email,
MIN(id) as id
FROM emails
GROUP BY email
) AS b
ON a.email = b.email
AND a.id = b.id;