Count number of times value appears in particular column in MySQL
Take a look at the Group by function.
What the group by function does is pretuty much grouping the similar value for a given field. You can then show the number of number of time that this value was groupped using the COUNT function.
You can also use the group by function with a good number of other function define by MySQL (see the above link).
mysql> SELECT student_name, AVG(test_score) -> FROM student -> GROUP BY student_name;