TSQL - 从ID的最大价值在另一个表更新

Question

我需要一些帮助，最好的方式来实现以下几点：

源表：

tbl_ID name Row_id change_time 
1  test1 1    2016-01-01 09:00:00 
1  test2 2    2016-01-01 10:00:00 
50  test3 3    2016-02-01 09:00:00 
50  test4 4    2016-02-01 11:00:00 
66  test50 5    2016-03-01 11:00:00 

目标表：

tbl_ID name Row_id RecordStatus 
1  test1 1   Expired 
1  test2 2   Expired ----need to update this to 'New Record' 
50  test3 3   Expired 
50  test4 4   Expired ---- need to update this to 'New Record' 
66  test50 5   Expired ---- need to update this to 'New Record'   

我需要通过加入源表来更新目的地表记录状态列：

• tbl_ID
• Row_id列。

其中'change_time'是每个ID的MAX值。

关于代码的任何建议，我将不胜感激。

Answer 1

这应做到：

示例数据：

CREATE TABLE #temp(tbl_ID  INT, 
       name  VARCHAR(50), 
       Row_id  INT, 
       change_time DATETIME); 

INSERT INTO #temp 
VALUES 
     (1, 'test1', 1, '2016-01-01 09:00:00'), 
     (1, 'test2', 2, '2016-01-01 10:00:00'), 
     (50, 'test3', 3, '2016-02-01 09:00:00'), 
     (50, 'test4', 4, '2016-02-01 11:00:00'), 
     (66, 'test50', 5, '2016-03-01 11:00:00'); 

CREATE TABLE #temp2(tbl_ID  INT, 
       name   VARCHAR(50), 
       Row_id  INT, 
       RecordStatus VARCHAR(50)); 

INSERT INTO #temp2 
VALUES 
     (1, 'test1', 1, 'Expired'), 
     (1, 'test2', 2, 'Expired'), ----need to update this to 'New Record' 
     (50, 'test3', 3, 'Expired'), 
     (50, 'test4', 4, 'Expired'), ---- need to update this to 'New Record' 
     (66, 'test50', 5, 'Expired'); ---- need to update this to 'New Record' 

QUERY：

;WITH A 
    AS (SELECT *, 
      RANK() OVER(PARTITION BY tbl_ID ORDER BY change_time) AS Ranking 
     FROM #temp), 
    B 
    AS (SELECT A.* 
     FROM A 
      INNER JOIN 
        (SELECT tbl_ID, 
          MAX(Ranking) Ranking 
         FROM A 
         GROUP BY tbl_ID) AS B ON A.tbl_ID = B.tbl_ID 
              AND A.Ranking = B.Ranking) 
    UPDATE A 
     SET A.RecordStatus = 'New Record' 
    FROM #temp2 AS A 
     INNER JOIN B B ON A.tbl_ID = B.tbl_ID 
         AND A.Row_id = B.Row_id; 

结果：

SELECT * 
FROM #temp2;