Примеры команд SQL в рамках урока #12

-- Фильтрация строк с помощью предложения HAVING. Сортировка значений NULL
-- https://www.youtube.com/watch?v=MS0AdDy-ThA

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-- Примеры команд SQL в рамках урока #12


SELECT JOB_ID, DEPARTMENT_ID, COUNT(*) AS COUNT_JOB_ID
FROM EMPLOYEES
WHERE DEPARTMENT_ID IS NOT NULL
GROUP BY JOB_ID, DEPARTMENT_ID
;


SELECT JOB_ID, DEPARTMENT_ID, COUNT(*) AS COUNT_JOB_ID
FROM EMPLOYEES
WHERE DEPARTMENT_ID IS NOT NULL
GROUP BY JOB_ID, DEPARTMENT_ID
HAVING COUNT(*) >= 20
;


SELECT DEPARTMENT_NAME, MANAGER_ID
FROM DEPARTMENTS
ORDER BY MANAGER_ID ASC
;


SELECT DEPARTMENT_NAME, MANAGER_ID
FROM DEPARTMENTS
ORDER BY MANAGER_ID ASC NULLS FIRST
;