相関å??

相関å??ã?¯FROMå?¥ã?«ã?‚るテーブルã?«ã?¤ã?„ã?¦ä¸Žã?ˆã‚‹äº‹ã?Œã?§ã??ã€?æ–°ã?—ã?„å??å‰?ã€?別å??ã?¨ã?ªã‚Šã?¾ã?™ã€‚相関å??をスキーマå??ã?§é™?定ã?™ã‚‹ã?“ã?¨ã?¯ã?§ã??ã?¾ã?›ã‚“。

相関å??ã?¯æ›´æ–°å?¯èƒ½ã?ªåˆ—ã?«ä½¿ã?†ã?“ã?¨ã?¯ã?§ã??ã?¾ã?›ã‚“。仮ã?«ä½¿ã?ˆã?°SQL例外ã?Œç™ºç”Ÿã?—ã?¾ã?™ã€‚ 例ã?ˆã?°ã€?
SELECT c11 AS col1, c12 AS col2, c13 FROM t1 FOR UPDATE of c11,c13
ã?¨ã?„ã?†ä¾‹ã?§ã?¯ã€?相関å??ã‚’c11ã?®col1ã?«ä½¿ã?†ã?“ã?¨ã?¯ã?§ã??ã?¾ã?›ã‚“。ã?ªã?œã?ªã‚‰ã€?c11ã?¯FOR UPDATEã?«ã?‚る列ã? ã?‹ã‚‰ã?§ã?™ã€‚ ã??れã?«å¯¾ã?—ã?¦ç›¸é–¢å??ã‚’c12ã?«ä½¿ã?†ã?“ã?¨ã?¯ã?§ã??ã?¾ã?™ã€‚ã?“れã?¯FOR UPDATEã?«ã?ªã?„ã?‹ã‚‰ã?§ã?™ã€‚

æ§‹æ–‡

SQL92識別�

例

-- Cã?¯ç›¸é–¢å??ã?§ã?™ã€‚
SELECT C.NAME
FROM SAMP.STAFF C