Extra Fields with SQL MIN() & GROUP BY

Question

When using the SQL MIN() function, along with GROUP BY, will any additional columns (not the MIN column, or one of the GROUP BY columns) match the data in the matching MIN r

Answer 1

The fastest solution:

SET @dep := '';
SELECT * FROM (
  SELECT * FROM `employee` ORDER BY `department`, `salary`
) AS t WHERE IF ( @dep = t.`department`, FALSE, ( @dep := t.`department` ) OR TRUE );