如何獲得最大記錄上的其他字段庫？

Question

我創建了一個臨時表，存儲客戶的詳細信息，我想查詢該組由CustomerNo數據並顯示的ImagePath如果ISDEFAULT設置1

CREATE TABLE #Temp 
(ID varchar(100), CustomerNo varchar(10), IsDefault int, ImagePath varchar(100), ViewCount int) 

INSERT INTO #Temp 
SELECT '1', 'AC1234', 1, 'xxx1.jpg', 12 UNION ALL 
SELECT '2', 'AC1234', 0, 'xxx2.jpg', 42 UNION ALL 
SELECT '3', 'AC1234', 0, 'xxx3.jpg', 15 UNION ALL 
SELECT '4', 'AC1235', 0, 'xxx4.jpg', 16 UNION ALL 
SELECT '5', 'AC1236', 1, 'xxx5.jpg', 13 UNION ALL 
SELECT '6', 'AC1234', 0, 'xxx6.jpg', 56 UNION ALL 
SELECT '7', 'AC1235', 1, 'xxx7.jpg', 17 

SELECT * FROM #Temp 
SELECT CustomerNo, MAX(IsDefault) as IsDefault, Sum(ViewCount) as ViewCount FROM #Temp 
GROUP BY CustomerNo 

DROP TABLE #Temp 

結果：

CustomerNo IsDefault ViewCount 
---------- ----------- ----------- 
AC1234  1   125 
AC1235  1   33 
AC1236  1   13 

我可以有這樣的結果（如果「IsDefault」= 1，顯示ImagePath？）？

CustomerNo IsDefault ViewCount ImagePath 
---------- ----------- ----------- ----------- 
AC1234  1   125   xxx1.jpg 
AC1235  1   33   xxx4.jpg 
AC1236  1   13   xxx5.jpg 

非常感謝！

Answer 1

假設只有一個記錄有ISDEFAULT標誌爲1，這將這樣的伎倆：

CREATE TABLE #Temp (
    ID varchar(100) 
    , CustomerNo varchar(10) 
    , IsDefault int 
    , ImagePath varchar(100) 
    , ViewCount int 
); 

INSERT INTO #Temp 
SELECT '1', 'AC1234', 1, 'xxx1.jpg', 12 UNION ALL 
SELECT '2', 'AC1234', 0, 'xxx2.jpg', 42 UNION ALL 
SELECT '3', 'AC1234', 0, 'xxx3.jpg', 15 UNION ALL 
SELECT '4', 'AC1235', 0, 'xxx4.jpg', 16 UNION ALL 
SELECT '5', 'AC1236', 1, 'xxx5.jpg', 13 UNION ALL 
SELECT '6', 'AC1234', 0, 'xxx6.jpg', 56 UNION ALL 
SELECT '7', 'AC1235', 1, 'xxx7.jpg', 17 
; 

with CustomerReport (CustomerNo, ViewCount) as 
    (SELECT t.CustomerNo, Sum(t.ViewCount) ViewCount 
     FROM #Temp t 
     GROUP BY t.CustomerNo) 
Select q1.CustomerNo, q1.ViewCount 
     , (Select ImagePath 
      from #Temp 
      where #Temp.CustomerNo = q1.CustomerNo 
      and #Temp.IsDefault = 1) ImgPath 
    from CustomerReport q1 
; 

drop table #temp 
; 

據我所知，您需要MS-SQL 2008+獲得的CTE語法的支持。