SQL更新表中的所有行，除了一些行，複合主鍵

Question

我正在努力與SQL語句。

我想更新所有的行，除了一些，在一個複合主鍵表。

這就是我現在做的事：

UPDATE Products SET Active = 0 

_

UPDATE Products SET Active = 1 
WHERE (Id_A = 1 AND Id_B = 1 AND Id_C = 1) OR 
     (Id_A = 1 AND Id_B = 2 AND Id_C = 1) OR 
     (Id_A = 5 AND Id_B = 8 AND Id_C = 3) OR 
     . 
     . 
     . 
     etc 

這工作，但我不喜歡它。我希望能夠一氣呵成。

有沒有辦法在SQL中做到這一點？

Answer 1

你的意思是這樣的：

UPDATE Products SET Active = CASE WHEN 
     (Id_A = 1 AND Id_B = 1 AND Id_C = 1) OR 
     (Id_A = 1 AND Id_B = 2 AND Id_C = 1) OR 
     (Id_A = 5 AND Id_B = 8 AND Id_C = 3) OR 
     . 
     . 
     . 
     THEN 1 ELSE 0 END 

Answer 2

你可以使用一個更新語句內的情況下，體現在哪裏？

喜歡的東西

UPDATE Products 
    set Active = CASE WHEN (Id_A = 1 AND Id_B = 1 AND Id_C = 1) THEN 1 
         WHEN (Id_A = 1 AND Id_B = 2 AND Id_C = 1) THEN 1       
         . 
         . 
         . 
         ELSE 0 END 

Answer 3

在某些SQL產品，可以進一步簡化語法內CASE，清除多個AND和OR一個簡單IN：

UPDATE Products 
SET Active = CASE WHEN 
     (Id_A, Id_B, Id_C) IN 
     ((1, 1, 5), (1, 2, 1), (5, 8, 3) ...) 
      THEN 1 ELSE 0 
      END ; 

---

另一件事要考慮的是如果表格有很多行（如數百萬或數十億）並且只有很小的百分比被設置爲Active=1，它可能會更有效地已更新所做的是2個陳述，類似於你從一開始有什麼，假設你有(Active)索引（或(Active=1)部分索引）：

UPDATE Products SET Active = 0 WHERE Active = 1 ; 

UPDATE Products SET Active = 1 WHERE ... ;