SSMS SQL - 将表中的一行与上一行进行比较 - 状态更改

Question

我使用的表格包含每周机会记录及其各自的状态。我想比较机会的最新状态和之前的一周（例如：从勘探到谈判的状态变化）。我希望将本周与之前一周相比具有更改值的所有内容都插入到新表中。注意：在本表中为Week，0表示当前周，1表示前一周，2表示，前两周等，等等。

表历史记录：

+--------+---------+-------------+-----+
|Acc_Num | Opp_Num |    Stage    | Week|
+--------+---------+-------------+-----+
|   1    |    1    |     Won     |  0  |
+--------+---------+-------------+-----+
|   1    |    1    | Negotiation |  1  |
+--------+---------+-------------+-----+
|   1    |    1    | Prospecting |  2  |
+--------+---------+-------------+-----+
|   1    |    2    | Prospecting |  0  |
+--------+---------+-------------+-----+
|   1    |    2    | Prospecting |  1  |
+--------+---------+-------------+-----+
|   2    |    1    | Negotiation |  0  |
+--------+---------+-------------+-----+
|   2    |    1    | Prospecting |  1  |
+--------+---------+-------------+-----+

目标表前：

+--------+---------+-------------+-----+
|Acc_Num | Opp_Num |    Stage    | Week|
+--------+---------+-------------+-----+
|   1    |    1    |     Won     |  0  |
+--------+---------+-------------+-----+
|   1    |    1    | Negotiation |  1  |
+--------+---------+-------------+-----+
|   2    |    1    | Negotiation |  0  |
+--------+---------+-------------+-----+
|   2    |    1    | Prospecting |  1  |
+--------+---------+-------------+-----+

我坚持比较前一周的阶段的第一步。这是我尝试但不工作的SQL代码：

SELECT *
INTO Goal_Table
FROM (
SELECT  Acc_Num
        ,Opp_Num
        ,Stage
        ,Week
        ,CONCAT(Acc_Num, Opp_Num,Week) AS Unq_ID
        FROM Table_History) as A
Left Join
(SELECT  Acc_Num
        ,Opp_Num
        ,Stage
        ,Week
        ,CONCAT(Acc_Num, Opp_Num,Week) AS Unq_ID
        FROM Table_History) as B
ON A.Unq_ID=B.Unq_ID AND A.Week=B.Week-1

我一直收到有关列名称需要唯一的错误。这是实际的错误文本：“每个表中的列名必须是唯一的。表'Goal_Table'中的列名'Acc_Num'被指定多次。”

感谢您的帮助或指导

Answer 1

使用分析功能可以更轻松地完成这项工作，分析功能更易于阅读，甚至更快。我提供了一个使用t-sql的例子，因为你引用了ssms：

create table dbo.Table_History
(
    Acc_Num int,
    Opp_Num int,
    Stage nvarchar(50),
    WeekNumber int
)
insert into dbo.Table_History
values
    (1,1,'won',0),
    (1,1,'Negotiation',1),
    (1,1,'Prospecting',2),
    (1,2,'Prospecting',0),
    (1,2,'Prospecting',1),
    (2,1,'Negotiation',0),
    (2,1,'Prospecting',1)

WITH CompareWeeks AS
(
    SELECT
        Acc_Num AS Acc_Num,
        Opp_Num AS Opp_Num,
        Stage AS Stage_Cur,
        WeekNumber as WeekNumber_cur,
        lag(Stage) over (partition by Acc_Num, Opp_Num order by WeekNumber desc) AS Stage_prev,
        lag(WeekNumber) over (partition by Acc_Num, Opp_Num order by WeekNumber desc) as WeekNumber_prev
    FROM dbo.Table_History
)
SELECT
    Acc_Num,
    Opp_Num,
    Stage_Cur,
    WeekNumber_cur
--INTO dbo.GoalTable
FROM CompareWeeks
WHERE Stage_Cur <> Stage_prev and Stage_prev is not null

请注意，上面提供的示例似乎并不一致。你没有考虑（1,1）的第一行，但你做（2,1），即使没有一周比较。