pratica-group-by.sql

-- 1
SELECT COUNT("endDate") AS "currentExperiences" FROM experiences;
-- SELECT COUNT(*) AS "currentExperiences" FROM experiences WHERE "endDate" IS NOT NULL;
-- 2
SELECT "userId" AS id, COUNT(*) AS educations FROM educations GROUP BY "userId" ORDER BY id ASC;
-- 3
SELECT users.name as writer, COUNT(*) as "testimonialCount" from testimonials JOIN users ON users.id = testimonials."writerId" GROUP BY users.name ORDER BY users.name ASC;
-- 4
SELECT MIN(jobs.salary) AS "maximumSalary", roles.name AS "role" FROM roles JOIN jobs ON roles.id = jobs."roleId" WHERE jobs.active = true GROUP BY roles.name ORDER BY "maximumSalary";