INNER JOIN ??????

INNER JOIN??????????????????????????????????????????????????????????????????JOIN ???????????????

??????

?????? [ INNER ] JOIN ?????? { ON ????????? }

ON????????????????????????????????????????????????????????????????????????

ON?????????????????????????????????????????????????????????????????????????????????????????????SELECT????????????????????????????????????????????? ??????????????????ON????????????????????????????????????????????? 
SELECT *
FROM SAMP.EMPLOYEE INNER JOIN SAMP.STAFF
ON EMPLOYEE.SALARY < STAFF.SALARY

ON???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????(?????????????????????????????????)

-- EMP_ACT???EMPLOYEE?????????????????????????????????
-- EMP_ACT??????????????????????????????????????????
-- EMPLOYEE????????????????????????????????????(LASTNAME)????????????????????????
-- ???????????????
SELECT SAMP.EMP_ACT.*, LASTNAME
     FROM SAMP.EMP_ACT JOIN SAMP.EMPLOYEE
     ON EMP_ACT.EMPNO = EMPLOYEE.EMPNO
-- EMPLOYEE???DEPARTMENT??????????????????????????????
-- 1930???????????????????????????(BIRTDATE)????????????????????????
-- ???????????????(EMPNO)?????????????????????(LASTNAME)???
-- ????????????(EMPLOYEE???????????????WORKDEPT??????DEPARTMENT???????????????DEPTNO)???
-- ?????????(DEPTNAME)??????????????????
SELECT EMPNO, LASTNAME, WORKDEPT, DEPTNAME 
     FROM SAMP.EMPLOYEE JOIN SAMP.DEPARTMENT 
     ON WORKDEPT = DEPTNO 
     AND YEAR(BIRTHDATE) < 1930

-- VALUES????????????????????????????????????(select????????????)???????????????"??????"??????????????? 
-- ?????????????????????????????????????????????????????????"R1"???"R2"?????????2??????"x"???????????????
-- ??????????????????????????????????????????
SELECT *
FROM (VALUES (3, 4), (1, 5), (2, 6))
AS VALUESTABLE1(C1, C2)
JOIN (VALUES (3, 2), (1, 2),
(0, 3)) AS VALUESTABLE2(c1, c2)
ON VALUESTABLE1.c1 = VALUESTABLE2.c1
-- This results in:
-- C1         |C2         |C1         |2
-- -----------------------------------------------
-- 3          |4          |3          |2
-- 1          |5          |1          |2
 
  
-- ?????????????????????????????????????????????????????????????????????????????????

SELECT DEPTNO, DEPTNAME, EMPNO, LASTNAME
	FROM DEPARTMENT INNER JOIN EMPLOYEE
	ON MGRNO = EMPNO

-- ???????????????????????????????????????????????????
-- ??????????????????????????????????????????????????????????????????
SELECT E.EMPNO, E.LASTNAME, M.EMPNO, M.LASTNAME	
	FROM EMPLOYEE E INNER JOIN	
	DEPARTMENT INNER JOIN EMPLOYEE M 
        ON MGRNO = M.EMPNO
        ON E.WORKDEPT = DEPTNO
???????????????: JOIN ??????