Aggregate Functions

Basic

SELECT AVG(salary) AS avg FROM test_emp;
  • Count the number of matching fields (COUNT)
SELECT COUNT(*) AS count FROM test_emp;
  • Count the number of distinct values in matching documents (COUNT(DISTINCT)
SELECT COUNT(DISTINCT hire_date) AS count FROM test_emp;
  • Find the maximum value in matching documents (MAX)
SELECT MAX(salary) AS max FROM test_emp;
  • Find the minimum value in matching documents (MIN)
SELECT MIN(emp_no) AS min FROM test_emp;
  • Sum all values of matching documents (SUM).
SELECT SUM(salary) FROM test_emp;