Question

我有一个名为Types的表，数据类似于：

Item_Name 

Hardware \ Hardware Laptop \ Display
Application \ Application Configuration Request
Application \ Application File Request
Application

我正在尝试将它们分成3个不同的列。所以尝试通过以下查询来实现：

select parsename(replace([Item_Name],'\','.'),3) as First,
 parsename(replace([Item_Name],'\','.'),2) as Second,
 parsename(replace([Item_Name],'\','.'),1) as third
from dbo.Types

但我没有得到我想要的输出的确切结果：

First          Second                                      Third
Hardware       Hardware Laptop                             Display
Application    Application Configuration Request           NULL
Application    Application File Request                    NULL
Application    NULL                                        NULL

但我得到的输出为：

First          Second                          Third
Hardware       Hardware Laptop                 Display
NULL           Application                     Application Configuration Request           
NULL           Application                     Application File Request                    
NULL           NULL                            Application

Answer 1

这可能很有用

Declare @t table(Item_Name Varchar(100))
Insert Into @t 
Select 'Hardware \ Hardware Laptop \ Display' Union All 
Select 'Application \ Application Configuration Request' Union All
Select 'Application \ Application File Request' Union All
Select 'Application'

;WITH CTE AS(
SELECT 
    Item_Name
    ,NoOfOccurance = (LEN(Item_Name) - LEN(REPLACE(Item_Name, '\', ''))) 
    ,New_Item_Name = CASE (LEN(Item_Name) - LEN(REPLACE(Item_Name, '\', ''))) 
                         WHEN 0 THEN 'Col1 \ Col2 \ ' +Item_Name
                         WHEN 1 THEN 'Col1 \ ' +Item_Name 
                         ELSE Item_Name
                     END
FROM @t)
,cte2 AS(
SELECT 
    [First] = LEFT(New_Item_Name,CHARINDEX('\',New_Item_Name,0)-1)  
    , [Second] = SUBSTRING(
                 New_Item_Name
                 ,CHARINDEX('\',New_Item_Name,0)+1
                 ,CHARINDEX('\',SUBSTRING(New_Item_Name,CHARINDEX('\',New_Item_Name,0)+1,len(New_Item_Name)),0)-1
               )
    ,[Third] = REVERSE(LEFT(REVERSE (New_Item_Name),CHARINDEX('\',REVERSE (New_Item_Name),0)-1))

FROM CTE)
SELECT
    [First] = CASE WHEN LTRIM(RTRIM([First])) = 'Col1' THEN REPLACE([First], 'Col1', NULL) ELSE [First] END
    ,[Second] = CASE WHEN LTRIM(RTRIM([Second])) = 'Col2' THEN REPLACE([Second], 'Col2', NULL) ELSE [Second] END 
    ,[Third]    
FROM Cte2

//结果

First   Second  Third
Hardware     Hardware Laptop     Display
NULL     Application     Application Configuration Request
NULL     Application     Application File Request
NULL    NULL     Application

Answer 2

我认为这种蛮力，但它有效。我们的想法是在末尾添加足够的斜杠来创建一个全名。这将推动事情：

with types as (select 'Hardware \ Hardware Laptop \ Display' as item_name union all
               select 'Application \ Application Configuration Request' union all
               select 'Application \ Application File Request' union all
               select 'Application'
              )
select parsename(replace([Item_Name]+suffix, '\', '.'), 3) as First,
       parsename(replace([Item_Name]+suffix, '\', '.'), 2) as Second,
       parsename(replace([Item_Name]+suffix, '\', '.'), 1) as third
from (select item_name, LEN(Item_name) - LEN(replace(item_name, '\', '')) as numslash,
             REPLICATE('. ', 2-(LEN(Item_name) - LEN(replace(item_name, '\', '')))) as suffix
      from Types
     ) t

一个细微的区别是，这会为空插槽产生空格而不是NULL。如果你想要NULL，你需要额外的逻辑。

Answer 3

WITH CTE AS(
 SELECT CASE LEN(Item_Name)-LEN(REPLACE(Item_Name,'\','')) WHEN 2 THEN [Item_Name] WHEN 1 THEN  
         [Item_Name]+'.' Else [Item_Name]+'..' as Item_Name
 FROM dbo.Types 
 )
SELECT parsename(Item_Name,'\','.'),3) as First,
       parsename(Item_Name,'\','.'),2) as Second,
       parsename(Item_Name,'\','.'),1) as third 
FROM CTE

将字符串中的值提取到多个列中

3 个答案: