的結果

Question

SQL Case語句我有以下SQL查詢：

SELECT IIF(clock_to - clock_at_from < 0, 
      12 - (clock_at_from - clock_to), 
      clock_to - clock_at_from) AS clock_pos 
FROM Condition 

從1-10

我覺得我要瓶坯上clock_pos CASE語句輸出的數字，其中

If clock_pos = 1 value = 3 
If clock_pos = 2 value = 4 
If clock_pos > 3 value = 5 

然後添加最終結果作爲條件表中的新列...

但我不是請注意如何使用名爲clock_pos的結果編寫此代碼，或者完全有更好的方法。

@EDIT按照TONY嵌套如果嘗試。我無法做出額外如果statment

SELECT IIF(clock_to - clock_at_from < 0, 
      IIF(12 - (clock_at_from - clock_to) >= 3, 5, 12 - (clock_at_from - clock_to)), 
      clock_to - clock_at_from) as clock_pos 
FROM Conditions 

Answer 1

MS訪問SQL實際上允許使用計算列在相同的查詢中：

SELECT IIF(clock_to - clock_at_from < 0, 
      12 - (clock_at_from - clock_to), 
      clock_to - clock_at_from) AS clock_pos, 
     IIF(clock_pos = 1, 3, 
      IIF(clock_pos = 2, 4, 
       IIF(clock_pos > 3, 5, NULL))) As clock_pos_value 
FROM Condition 

Answer 2

似乎很簡單，如果你使用子查詢到CASE邏輯轉換爲嵌套IIF()：

SELECT IIF(clock_pos = 1, 3 
      IIF(clock_pos = 2, 4, 
       IIF(clock_pos > 3, 5, NULL) 
       ) 
     ) as [value] 
FROM (SELECT IIF(clock_to - clock_at_from < 0, 
       IIF(12 - (clock_at_from - clock_to) >= 3, 
        5, 12 - (clock_at_from - clock_to) 
        ), clock_to - clock_at_from 
       ) as clock_pos 
     FROM Conditions 
    ) as c