Sql 使用CTE拆分表中的行
我在SQLServer2008R2中的表中有以下行Sql 使用CTE拆分表中的行,sql,sql-server,sql-server-2008-r2,common-table-expression,Sql,Sql Server,Sql Server 2008 R2,Common Table Expression,我在SQLServer2008R2中的表中有以下行 +-------------------------------------------+ | ID EntryType dt price | +-------------------------------------------+ | 14 4 2012-11-07 0.025000 | | 16 5 2012-11-07 0.026
+-------------------------------------------+
| ID EntryType dt price |
+-------------------------------------------+
| 14 4 2012-11-07 0.025000 |
| 16 5 2012-11-07 0.026000 |
| 18 6 2012-11-07 0.026000 |
| 20 7 2012-11-07 0.026000 |
+-------------------------------------------+
我想做的是根据EntryType排列行EntryType不会改变
For EntryType = 4 (1 row)
For EntryType = 5 (2 row)
For EntryType = 6 (3 row)
For EntryType = 7 (9 row)
dt字段将在一个月内递增,因此输出如下所示:
+-----------+-----------+-------+
| EntryType | dt | Price |
+-----------+-----------+-------+
| 4 | 11/7/2012 | 0.024 |
| 5 | 12/7/2012 | 0.025 |
| 5 | 1/7/2013 | 0.025 |
| 6 | 2/7/2013 | 0.026 |
| 6 | 3/7/2013 | 0.026 |
| 6 | 4/7/2013 | 0.026 |
| 7 | 5/7/2013 | 0.027 |
| 7 | 6/7/2013 | 0.027 |
| 7 | 7/7/2013 | 0.027 |
| 7 | 8/7/2013 | 0.027 |
| 7 | 9/7/2013 | 0.027 |
| 7 | 10/7/2013 | 0.027 |
| 7 | 11/7/2013 | 0.027 |
| 7 | 12/7/2013 | 0.027 |
| 7 | 1/7/2014 | 0.027 |
+-----------+-----------+-------+
使用CTE和SQL可以做到这一点吗?不确定CTE是否可以做到这一点,因为我无法分辨EntryType和of row之间的任何逻辑 对于这个问题,我认为构建一个包含所需行数的临时表更容易
DECLARE @Entry TABLE(EntryType INT, seq INT)
INSERT INTO @Entry (EntryType , seq) VALUES
(4,1)
,(5,1)
,(5,2)
,(6,1)
...
,(7,1)
..
,(7,9)
之后,一个简单的查询将得到相同的结果
SELECT t.EntryType , DATEADD(MONTH,e.seq, t.dt) as dt,t.Price
FROM YourTable t
INNER JOIN @Entry e
ON t.EntryType = e.EntryType
以下是一种在以下情况下执行此操作的方法: 这是展示这件作品的图片 有几件事: 我认为,随着记录数量的增加,使用a而不是递归来乘法记录可能会更好。您将交叉连接理货表,并让where子句根据RecordCount限制记录 我看不出价格应该如何从输入变为输出。 我不知道您在哪里建立每个EntryType的记录计数,因此我已将其添加到另一个CTE中。 唯一一件事我不明白的是,以什么标准来获得价格
演示我应该提到它。SQL Server我想我不明白这一点…:EntryType与您希望为其返回的行数之间是否存在某种逻辑关系?或者这些信息是可以从某种查找表或其他东西中读取的?价格从输入到输出是如何变化的?事实上是一样的,很好!
;with RecordCounts as (
-- Establish row counts for each EntryType
select 4 as EntryType, 1 as RecordCount
union all select 5, 2
union all select 6, 3
union all select 7, 9
), PricesCte as (
-- Get initial set of records
select ID, p.EntryType, (select min(dt) from MyTable) as dt, price, 1 as RecordNum
from MyTable p
join RecordCounts c on p.EntryType = c.EntryType -- Only get rows where we've established a RecordCount
-- Add records recursively according to RecordCount
union all
select ID, p.EntryType, dt, price, RecordNum + 1
from PricesCte p
join RecordCounts c on p.EntryType = c.EntryType
where RecordNum + 1 <= c.RecordCount
)
select EntryType,
dateadd(mm, row_number() over (order by EntryType, ID) - 1, dt) as dt,
price
from PricesCTE
order by EntryType
option (maxrecursion 0) -- Infinite recursion, default limit is 100
;WITH e (ID, EntryType, row, dt, Price, [Len])
AS
(
SELECT ID, EntryType, CASE EntryType WHEN 4 THEN 1
WHEN 5 THEN 2
WHEN 6 THEN 3
WHEN 7 THEN 9 END AS row,
dt, Price, 0 AS [Len]
FROM dbo.your_table
), x (ID, EntryType, row, dt, Price, [Len]) AS
(
SELECT ID, EntryType, row, dt, Price, 1
FROM e
UNION ALL
SELECT e.ID, e.EntryType, e.row, e.dt, e.Price, x.[Len] + 1
FROM e , x
WHERE e.ID = x.ID AND e.row > x.[Len]
)
SELECT EntryType, DATEADD(mm, ROW_NUMBER() OVER(ORDER BY EntryType)-1, dt) AS dt, Price
FROM x
ORDER BY EntryType