Answers for "table with distinct values for all column sql"

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;

inspecting a column unique/distinct values in SQL

#The SELECT DISTINCT statement is used to return only distinct (or unique) values.
SELECT
	DISTINCT(column_name)
FROM
	database_name.table_name