SQL Server多次拆分单个列

Question

我有一个与我要打破部分分为两个级别与列堆叠数据列的数据库表.以下是数据示例(为保护无辜者而改变数据:):

表

ID = varchar(100)
CarData = varchar(1000)

ID       CarData
1        Nissan:blue:20000,Ford:green:10000
2        Nissan:steel:20001,Ford:blue:10001,Chevy:blue:10000,Ford:olive:10000
** Note that cardata can is not fixed, and can have many cars in it

输出所需:

ID   Manufacture    Color     Cost
1    Nissan         Blue      20000
1    Ford           green     10000
2    Nissan         steel      20001
... and on

所以说明白我需要打破第一个堆叠字段,这是一个逗号并为其创建一行,然后将第二个堆叠字段分解为列.

任何帮助将不胜感激.

Answer 1

-- Sample data
declare @T table(ID int, CarData varchar(100))
insert into @T values 
(1,        'Nissan:blue:20000,Ford:green:10000'),
(2,        'Nissan:steel:20001,Ford:blue:10001,Chevy:blue:10000,Ford:olive:10000')

-- Recursice CTE to get one row for each car
;with cte(ID, Car, CarData) as
(
  select ID,
         cast(substring(CarData+',', 1, charindex(',', CarData+',')-1) as varchar(100)),
         stuff(CarData, 1, charindex(',', CarData), '')+','
  from @T
  where len(CarData) > 0
  union all
  select ID,
         cast(substring(CarData, 1, charindex(',', CarData)-1) as varchar(100)),
         stuff(CarData, 1, charindex(',', CarData), '')
  from cte
  where len(CarData) > 0
)
-- Use parsename to split the car data
select ID,
       parsename(replace(Car, ':', '.'), 3) as Manufacture,
       parsename(replace(Car, ':', '.'), 2) as Color,
       parsename(replace(Car, ':', '.'), 1) as Cost
from cte
order by ID

结果:

ID  Manufacture  Color   Cost
--  -----------  ------   -----
1   Nissan       blue    20000
1   Ford         green   10000
2   Nissan       steel   20001
2   Ford         blue    10001
2   Chevy        blue    10000
2   Ford         olive   10000

编辑1

parsename如果颜色,成本或制造商名称包含a,您将遇到问题..如果是这种情况,你应该尝试这样做.

-- Sample data
declare @T table(ID int, CarData varchar(100))
insert into @T values 
(1,        'Nissan:blue:20000,Ford:green:10000'),
(2,        'Nissan:steel:20001,Ford:blue:10001,Chevy:blue:10000,Ford:olive:10000')

-- Recursice CTE to get one row for each car
;with cte(ID, Car, CarData) as
(
  select ID,
         cast(substring(CarData+',', 1, charindex(',', CarData+',')-1) as varchar(100)),
         stuff(CarData, 1, charindex(',', CarData), '')+','
  from @T
  where len(CarData) > 0
  union all
  select ID,
         cast(substring(CarData, 1, charindex(',', CarData)-1) as varchar(100)),
         stuff(CarData, 1, charindex(',', CarData), '')
  from cte
  where len(CarData) > 0
)
-- Split the car data with substring
select ID,
       substring(Car, 1, P1.Pos-1) as Manufacture,
       substring(Car, P1.Pos+1, P2.Pos-P1.Pos-1) as Color,
       substring(Car, P2.Pos+1, len(Car)-P2.Pos) as Cost
from cte
  cross apply (select charindex(':', Car)) as P1(Pos)
  cross apply (select charindex(':', Car, P1.Pos+1)) as P2(Pos)
order by ID

Answer 2

使用此字符串拆分函数生成结果表。

我首先会dbo.split()使用 a,作为分隔符进行调用。然后您将得到一个项目列表，例如：

Nissan:blue:20000
Ford:green:10000
Nissan:steel:20001
Ford:blue:10001
Chevy:blue:10000
Ford:olive:10000

从那里您可以使用分隔符dbo.split()再次调用。:每次调用将恰好产生三个记录（假设您的设计至少是“正常”的）。

正如 @JNK 在他的评论中提到的，希望这不是您想要定期运行的东西。

编辑：

一些帮助您入门的示例代码：

SELECT *
INTO #YuckyCar
FROM (
  SELECT 1 ID, 'Nissan:blue:20000,Ford:green:10000' CarData
  UNION
  SELECT 2, 'Nissan:steel:20001,Ford:blue:10001,Chevy:blue:10000,Ford:olive:10000'
) T;

-- Shows logical step #1
SELECT ID, X.items MoreCarData
FROM #YuckyCar CROSS APPLY dbo.Split(CarData, ',') X;

-- Shows logical step #2
SELECT Q.ID, Y.items
FROM (
  SELECT ID, X.items MoreCarData
  FROM #YuckyCar CROSS APPLY dbo.Split(CarData, ',') X) Q CROSS APPLY dbo.Split(Q.MoreCarData, ':') Y

DROP TABLE #YuckyCar;

最后一部分的问题是您无法保证第 1 行 = 制造商、第 2 行 = 颜色、第 3 行 = 成本。