5.17. SQL Select Functions¶
5.17.1. Sum¶
SELECT SUM(experience)
FROM astronauts
WHERE agency = 'NASA';
5.17.2. Average¶
SELECT AVG(age)
FROM astronauts
WHERE agency = 'NASA';
5.17.3. Count¶
SELECT COUNT(id)
FROM astronauts
WHERE agency = 'NASA';
SELECT COUNT(DISTINCT agency)
FROM astronauts;
SELECT COUNT(DISTINCT mission_name)
FROM astronauts
WHERE agency = 'NASA';