如何使用此SQL語句執行左側子查詢或子查詢？

Question

我有幾個AA和left join，所以我想補充/合併這sql我的其他查詢中：

SELECT 
    A.ID 
FROM 
    Table1 as A 
LEFT JOIN 
    (SELECT 
     T.ID, T.TRF_TAKEN, 
     SUM(CASE WHEN CAST([UNT_TRNSFER] AS FLOAT) = 0 
        THEN CAST([TRF_TAKEN] AS FLOAT) 
        ELSE ISNULL([UNT_TRNSFER], 0) 
      END) AS 'UNT_TRNSFER' 
    FROM TRNS_C as T 
    GROUP BY ID;) ON A.ID = TransfC.ID 
WHERE 
    A.ID = 1; 

ERROR

列「TRNS_C.TRF_TAKEN」在選擇列表中，因爲無效它不包含在聚合函數或GROUP BY子句中。

Answer 1

從GROUP BY ID;)刪除;，加T.TRF_TAKEN到GROUP BY條款並添加表的別名Transfc，你加入了。

SELECT A.ID, Transfc.UNT_TRNSFER 
FROM Table1 AS A 
LEFT JOIN (
    SELECT T.ID, T.TRF_TAKEN, 
      SUM(CASE WHEN CAST([UNT_TRNSFER] AS FLOAT) = 0 THEN CAST([TRF_TAKEN] AS FLOAT) 
      ELSE ISNULL([UNT_TRNSFER], 0) END) AS 'UNT_TRNSFER' 
      FROM TRNS_C as T 
      GROUP BY T.ID, T.TRF_TAKEN 
) Transfc 
ON A.ID = TransfC.ID 
WHERE A.ID = 1; 

Answer 2

你只需要把你的非聚合字段放到GROUP BY中。您正在要求它按EMPLID進行分組，但您只選擇了t.ID和t.TRF_Taken。

select A.ID 
from Table1 as A 

LEFT JOIN (
    SELECT T.ID, T.TRF_TAKEN, 
      SUM(CASE WHEN CAST([UNT_TRNSFER] AS FLOAT) = 0 THEN CAST([TRF_TAKEN] AS FLOAT) ELSE ISNULL([UNT_TRNSFER], 0) END) AS 'UNT_TRNSFER' 
      FROM TRNS_C as T 
      GROUP BY T.ID, T.TRF_TAKEN; 
    ) Transfc 
ON A.ID = TransfC.ID 
    Where A.ID = 1; 

Answer 3

作爲一個說明，在你的問題查詢大約相當於：

SELECT A.ID 
FROM Table1 A 
WHERE A.ID = 1; 

您left join可能做的是乘以行數的唯一的事情。這似乎不太可取。