The MIN function returns the minimum value of a collection of values.
The expression is a column name, numeric expression, or literal.
Null values are removed.
The argument values can be character, numeric, or datetime.
The result can be character, numeric, datetime, or NULL, if there are no values.
The minimum of no rows is NULL, not zero.
The keyword DISTINCT can be used, but it serves no purpose and it doesn’t change the results.
The result is only as precise as the data types used in the expression.
The minimum with character data means the lowest sort order. See ORDER BY.

                                     MIN(expression)

                                               or

                              MIN(DISTINCT column-name) <– No difference in the result.

 To SELECT other columns associated with the MIN row, see the HAVING clause.