GROUP BY
The GROUP BY
command groups a result-set of rows, usually based on an aggregate function.
Syntax
SELECT column(s)
FROM table
GROUP BY column(s)
The aggregate function is usually applied on the same line as the SELECT command.
Example
The following example returns a result set of the number (count) of students from each country:
SELECT COUNT(student_name),birth_countryFROM studentsGROUP BY birth_country;