T-SQL连续组合行

Question

我有一个如下所示的表格.我想要的是彼此连续的行被组合在一起 - 对于每个"ID".列IsContinued标记下一行是否应与当前行组合

我的数据如下:

+-----+--------+-------------+-----------+----------+
| ID  | Period | IsContinued | StartDate | EndDate  |
+-----+--------+-------------+-----------+----------+
| 123 | 1      | 1           | 20180101  | 20180404 |
+-----+--------+-------------+-----------+----------+
| 123 | 2      | 1           | 20180501  | 20180910 |
+-----+--------+-------------+-----------+----------+
| 123 | 3      | 0           | 20181001  | 20181201 |
+-----+--------+-------------+-----------+----------+
| 123 | 4      | 1           | 20190105  | 20190228 |
+-----+--------+-------------+-----------+----------+
| 123 | 5      | 0           | 20190401  | 20190430 |
+-----+--------+-------------+-----------+----------+
| 456 | 2      | 1           | 20180201  | 20180215 |
+-----+--------+-------------+-----------+----------+
| 456 | 3      | 0           | 20180301  | 20180401 |
+-----+--------+-------------+-----------+----------+
| 456 | 4      | 0           | 20180501  | 20180530 |
+-----+--------+-------------+-----------+----------+
| 456 | 5      | 0           | 20180701  | 20180705 |
+-----+--------+-------------+-----------+----------+

我想要的最终结果是:

+-----+-------------+-----------+-----------+----------+
| ID  | PeriodStart | PeriodEnd | StartDate | EndDate  |
+-----+-------------+-----------+-----------+----------+
| 123 | 1           | 3         | 20180101  | 20181201 |
+-----+-------------+-----------+-----------+----------+
| 123 | 4           | 5         | 20190105  | 20190430 |
+-----+-------------+-----------+-----------+----------+
| 456 | 2           | 3         | 20180201  | 20180401 |
+-----+-------------+-----------+-----------+----------+
| 456 | 4           | 4         | 20180501  | 20180530 |
+-----+-------------+-----------+-----------+----------+
| 456 | 5           | 5         | 20180701  | 20180705 |
+-----+-------------+-----------+-----------+----------+

DDL声明:

CREATE TABLE #Period (ID INT, PeriodNr INT, IsContinued INT, STARTDATE DATE, ENDDATE DATE)
INSERT INTO #Period VALUES (123,1,1,'20180101', '20180404'),
                      (123,2,1,'20180501', '20180910'),
                      (123,3,0,'20181001', '20181201'),
                      (123,4,1,'20190105', '20190228'),
                      (123,5,0,'20190401', '20190430'),
                      (456,2,1,'20180201', '20180215'),
                      (456,3,0,'20180301', '20180401'),
                      (456,4,0,'20180501', '20180530'),
                      (456,5,0,'20180701', '20180705')

代码应该在SQL Server 2016上运行

谢谢!

Answer 1

这是一种方法：

with removeFluff as
(
SELECT *
FROM (
        SELECT ID, PeriodNr, IsContinued, STARTDATE, ENDDATE, LAG(IsContinued,1,2) OVER (PARTITION BY ID ORDER BY PERIODNR) Lag
        FROM #Period
     ) A
WHERE (IsContinued <> Lag) OR (IsContinued + Lag = 0)
)    
,getValues as
(
SELECT ID,
       CASE WHEN LAG(IsContinued) OVER (PARTITION BY ID ORDER BY PeriodNr) = 1 THEN LAG(PeriodNr) OVER (PARTITION BY ID ORDER BY PeriodNr) ELSE PeriodNr END PeriodStart,
       PeriodNr PeriodEnd,
       CASE WHEN LAG(IsContinued) OVER (PARTITION BY ID ORDER BY PeriodNr) = 1 THEN LAG(STARTDATE) OVER (PARTITION BY ID ORDER BY PeriodNr) ELSE STARTDATE END StartDate,
       EndDate,
       IsContinued
FROM removeFluff r
)

SELECT ID, PeriodStart, PeriodEnd, StartDate, EndDate
FROM getValues
WHERE IsContinued = 0

输出：

ID  PeriodStart PeriodEnd   StartDate   EndDate
123    1           3        2018-01-01  2018-12-01
123    4           5        2019-01-05  2019-04-30
456    2           3        2018-02-01  2018-04-01
456    4           4        2018-05-01  2018-05-30
456    5           5        2018-07-01  2018-07-05

方法：

• removeFluffcte 删除不重要的行。这些是不开始或结束段的记录（示例数据中的第 2 行）
• 现在绒毛已被去除，我们知道：
• A.) 该行本身是完整的 ( LAG(IsContinued) ... = 0)，即。上一行已完成
• B.) 该行需要上一行的“开始”信息 ( LAG(IsContinued) ... = 1)
• 我们将这两种情况应用到cteCASE的表达式中getValues
• 最后，结果被缩小到只有最终选择中的重要行IsContinued = 0。这是因为我们曾经LAG在“结束”数据行上获取“开始”数据，所以我们只想选择结束行