SQL - 從表格數據創建彙總統計

Question

我有以下表

Manager-category StartDate Enddate 
A     1/1/2002  2/2/2007 
B     1/5/2005  4/5/2005 
etc.... 

我需要創建彙總統計如下圖所示（摘要）

Year CountofCategoryA who started CountofCategoryB who started 
2003 
etc 

我可以進行更新生成上表對於每個單元格，在Access I中使用

UPDATE summary, 
     (A query that gives a count in a year) as counttab 
    SET summary.column = counttab.count 
WHERE summary.Year = currentyear 

我必須爲每個單元格運行此查詢是否存在更快/更高效的方式？

Answer 1

這聽起來像你正在尋找一個交叉表查詢：

TRANSFORM Count(*) AS Expr2 
SELECT Year([StartDate]) AS Expr1 
FROM SomeTable 
GROUP BY Year([StartDate]) 
PIVOT SomeTable.[Manager-category];