需要T-SQL的帮助2005

Question

我有两个表Employee和EmployeeLog（与除LogCreatedDate同一列）

列是这样的：

EmployeeID, EmployeeName, LastModifiedBy, ModifiedDate, 
ColumnA, ColumnB, ColumnC bla-bla-bla 

我需要T-SQL这给我输出如下表所示。

的ResultSet 1：

在每一个Employee表更新我插入EmployeeLog表的新行的当前值。

EmployeeLog表包含每个EmployeeID多个行，所以我需要先前和修改列中的当前值。

因此，我的第一步是我通过LogCreatedDate DESC获取TOP 2记录订单。现在我应该怎么做才能获得如表所示的输出？

的ResultSet 2：

感谢

Answer 1

试试这个：

DECLARE @EmployeeLog TABLE 
(
    EmployeeID int, 
    EmployeeName varchar(50), 
    LastModifiedBy varchar(50), 
    ModifiedDate datetime, 
    ColumnA varchar(50), 
    ColumnB varchar(50), 
    ColumnC varchar(50), 
    LogCreatedDate datetime 
) 

INSERT INTO @EmployeeLog VALUES (1, 'A', 'A', '2012-02-07', 'A', 'B', 'C', '2012-02-07') 
INSERT INTO @EmployeeLog VALUES (1, 'B', 'B', '2012-02-06', 'AA', 'BB', 'CC', '2012-02-06') 

; 
WITH Basics AS 
(
     SELECT *, ROW_NUMBER() OVER (ORDER BY LogCreatedDate DESC) as Entry 
     FROM @EmployeeLog 
),  PivotTable AS 
(
     SELECT EmployeeID, 
       LastModifiedBy, 
       ModifiedDate, 
       'ColumnA' ColumnName, 
       ColumnA ColumnValue, 
       LogCreatedDate, 
       Entry 
     FROM Basics 
     UNION ALL 
     SELECT EmployeeID, 
       LastModifiedBy, 
       ModifiedDate, 
       'ColumnB' ColumnName, 
       ColumnB ColumnValue, 
       LogCreatedDate, 
       Entry 
     FROM Basics 
     UNION ALL 
     SELECT EmployeeID, 
       LastModifiedBy, 
       ModifiedDate, 
       'ColumnC' ColumnName, 
       ColumnC ColumnValue, 
       LogCreatedDate, 
       Entry 
     FROM Basics 
) 
SELECT [Current].LastModifiedBy, [Current].ModifiedDate, 
     Previous.EmployeeID, Previous.ColumnName, 
     Previous.ColumnValue [Previous Value], 
     [Current].ColumnValue [Current Value] 
FROM PivotTable Previous 
JOIN PivotTable [Current] 
    ON Previous.EmployeeID = [Current].EmployeeID AND 
     Previous.ColumnName = [Current].ColumnName AND 
     Previous.Entry = [Current].Entry + 1