多個IN語句。這會返回良好的數據嗎？

Question

SELECT ['VISA CK - 021810$'].[ACCT NBR  #1], ['VISA CK - 021810$'].[ALT CUST NM #1], ['VISA CK - 021810$'].[LAST USED] 
FROM ['VISA CK - 021810$'] 
WHERE ['VISA CK - 021810$'].[ALT CUST NM #1] 
    IN (
     SELECT ['VISA CK - 021810$'].[ALT CUST NM #1] 
     FROM ['VISA CK - 021810$'] 
     GROUP BY ['VISA CK - 021810$'].[ALT CUST NM #1] 
      HAVING COUNT(['VISA CK - 021810$'].[ALT CUST NM #1]) > 1 
     ) 
    AND ['VISA CK - 021810$'].[ACCT NBR  #1] 
    IN (
     SELECT ['VISA CK - 021810$'].[ACCT NBR  #1] 
     FROM ['VISA CK - 021810$'] 
     GROUP BY ['VISA CK - 021810$'].[ACCT NBR  #1] 
      HAVING COUNT(['VISA CK - 021810$'].[ACCT NBR  #1]) > 1 
     ) 

Answer 1

使用改寫聯接：

SELECT t.[ACCT NBR  #1], 
     t.[ALT CUST NM #1], 
     t.[LAST USED] 
    FROM ['VISA CK - 021810$'] t 
    JOIN (SELECT ['VISA CK - 021810$'].[ALT CUST NM #1] 
      FROM ['VISA CK - 021810$'] 
     GROUP BY ['VISA CK - 021810$'].[ALT CUST NM #1] 
     HAVING COUNT(['VISA CK - 021810$'].[ALT CUST NM #1]) > 1) x ON x.[ALT CUST NM #1] = t.[ALT CUST NM #1] 
    JOIN (SELECT ['VISA CK - 021810$'].[ACCT NBR  #1] 
      FROM ['VISA CK - 021810$'] 
     GROUP BY ['VISA CK - 021810$'].[ACCT NBR  #1] 
     HAVING COUNT(['VISA CK - 021810$'].[ACCT NBR  #1]) > 1) y ON y.[ACCT NBR  #1] = t.[ACCT NBR  #1] 

確保它返回你所期望的數據 - 後調。假設你提供的查詢是正確的，JOIN通常比子查詢更受歡迎，但審查和比較執行計劃會告訴你什麼是最適合你的情況。

Answer 2

這是一個有效的SQL結構，但我們無法評論它是否有效。

你的意思是：在['VISA CK - 021810$']每一行，返回該行，如果我找到他們相對都[ACCT NBR #1]和[ALT CUST NM #1] IN子句

Answer 3

是的，它會返回良好的數據匹配。 WHERE子句將確保在使用AND時返回任何數據之前，兩個IN子句都受到尊重。