表副���

表副����複数�行を返�副�����。

スカラー副�����異�り�表副����以下�文脈�����能��。

FROM 節ã?®è¡¨å¼?ã?«ã?¦ä½¿ã‚?れã?Ÿå ´å?ˆã€?複数ã?®åˆ—ã‚’è¿”ã?™ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚

EXISTSã?§ã?¯ã€?*を使ã?†å ´å?ˆã?®ã?¿è¤‡æ•°ã?®åˆ—ã‚’è¿”ã?™ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚

INã‚„é™?定æ?¡ä»¶ã?§ã?¯ã€?å?˜åˆ—ã?®ã?¿è¿”ã?™ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚

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例

-- FROM節�表�����副���を使�。
SELECT VirtualFlightTable.flight_ID
FROM
    (SELECT flight_ID, orig_airport, dest_airport
    FROM Flights
    WHERE (orig_airport = 'SFO' OR dest_airport = 'SCL') )
AS VirtualFlightTable
-- FROM節�表�����副���(values�)を使�。
SELECT mycol1
FROM
    (VALUES (1, 2), (3, 4))
AS mytable (mycol1, mycol2)
-- EXISTS��副���を使�
SELECT *
FROM Flights
WHERE EXISTS
    (SELECT * FROM Flights WHERE dest_airport = 'SFO'
    AND orig_airport = 'GRU')
-- IN��副���を使�
SELECT flight_id, segment_number
FROM Flights
WHERE flight_id IN
    (SELECT flight_ID
    FROM Flights WHERE orig_airport = 'SFO'
    OR dest_airport = 'SCL')
-- 定�比較��副���を使�
SELECT NAME, COMM 
FROM STAFF 
WHERE COMM > 
(SELECT AVG(BONUS + 800)
     FROM EMPLOYEE
     WHERE COMM < 5000)