39.資料庫中有兩個資料表IN和NM如下，其中IN的主要鍵值為sid，NM的主要鍵值為sname。 試問IN join NM，結果會有多少筆資料? IN sid major --- 123 CS 456 CS NM Sname major ----- John CS Chris CS (A)2 (B)3 (C)4 (D)5 答案是(C) 我以為可以這樣寫 SELECT * FROM IN INNER JOIN NM ON IN.major=NM.major 看能不能合併成2筆 是哪裡搞錯了 @@ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 114.35.166.245
推carterdunk:你這樣寫，查詢結果也該是四筆喔07/03 15:56
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