SQL

sql average

SELECT AVG(column_name)
FROM table_name
WHERE condition;

how to find average in sql

SELECT FIRST_NAME FROM EMPLOYEES
WHERE SALARY = (SELECT AVG(SALARY) FROM EMPLOYEES);

how to do an average on a count sql

SELECT avg(count)
  FROM 
    (
    SELECT COUNT (*) AS Count
      FROM Table T
     WHERE T.Update_time =
               (SELECT MAX (B.Update_time )
                  FROM Table B
                 WHERE (B.Id = T.Id))
    GROUP BY T.Grouping
    ) as counts

sql average

SELECT student_name, avg(notes) FROM student_notes GROUP BY student_name;