Returns the minimum expression value found in each group of rows.
MIN ( expression | DISTINCT column-name )
expression The expression for which the minimum value is to be calculated. This is commonly a column name.
DISTINCT column-name Returns the same as MIN ( expression ), and is included for completeness.
The following statement returns the value 24903.000, representing the minimum salary in the employee table.
SELECT MIN ( salary ) FROM employee
Rows where expression is NULL are ignored. Returns NULL for a group containing no rows.