USE Study
GO

(SELECT * FROM EMPLOYEE WHERE DNO = 10)
UNION
(SELECT * FROM EMPLOYEE WHERE JOB = 'chief')

(SELECT * FROM EMPLOYEE WHERE DNO = 10)
INTERSECT
(SELECT * FROM EMPLOYEE WHERE JOB = 'chief')

(SELECT * FROM EMPLOYEE WHERE DNO = 10)
EXCEPT
(SELECT * FROM EMPLOYEE WHERE JOB = 'chief')

-- Áߺ¹ Çã¿ë ÇÕÁýÇÕ
(SELECT * FROM EMPLOYEE WHERE DNO = 10)
UNION ALL
(SELECT * FROM EMPLOYEE WHERE JOB = 'chief')

-- ¿ÜºÎ ÇÕÁýÇÕ (ÇÕº´ ȣȯ¼º[: ¼Ó¼º °³¼ö ¹× ŸÀÔ ÀÏÄ¡] ºÒÀÏÄ¡ ÇÒ ¶§)
(SELECT ENO, ENAME, DNO, NULL FROM EMPLOYEE)
UNION
(SELECT NULL, NULL, DNO, DNAME FROM DEPARTMENT)

-- Áý´Ü ¿¬»êÀÚ
SELECT AVG(SALARY) FROM EMPLOYEE

SELECT MAX(SALARY) AS MAXSALARY, MIN(SALARY) AS MINSALARY FROM EMPLOYEE

SELECT AVG(SALARY) AS AVERAGE, VAR(SALARY) AS VARIANCE, STDEV(SALARY) AS STANDARDDEVIATION FROM EMPLOYEE

SELECT * FROM EMPLOYEE
SELECT COUNT(*) AS NUMROW, COUNT(COMMISSION) FROM EMPLOYEE

SELECT * FROM EMPLOYEE
SELECT COUNT(JOB) AS JOB, COUNT(DISTINCT JOB) AS DISTJOB FROM EMPLOYEE

SELECT DNO, AVG(SALARY) AS AVGSAL FROM EMPLOYEE GROUP BY DNO

SELECT DNO, AVG(SALARY) AS AVGSAL FROM EMPLOYEE GROUP BY DNO HAVING MAX(SALARY) > 500

SELECT DNO, JOB, AVG(SALARY) AS AVGSAL FROM EMPLOYEE GROUP BY DNO, JOB ORDER BY DNO

SELECT DNO, JOB, AVG(SALARY) AS AVGSAL FROM EMPLOYEE GROUP BY DNO, JOB WITH ROLLUP

SELECT DNO, JOB, AVG(SALARY) AS AVGSAL FROM EMPLOYEE GROUP BY DNO, JOB WITH CUBE

SELECT DNO, JOB, AVG(SALARY) AS AVGSAL FROM EMPLOYEE GROUP BY GROUPING SETS (DNO, JOB) -- DNO, JOB µû·Î ÇÑ °ÍÀ» UNION Çؼ­ º¸¿©ÁÜ