用逗号分隔不同行中的值

Question

Hi I am trying to retrieve values from database. I have a row which has multiple image names separated by ",". I want to display them in different lines. I am using the following code which is working fine for two values. But even when I have three or more values then too it gives back only two. This is my query:

;with tmp(ImageURL,HeritageId) as
 (

select  LEFT(ImageURL, CHARINDEX(',',ImageURL+',')-1),
    STUFF(ImageURL, 1, CHARINDEX(',',ImageURL+','), '')
from shop.dbo.Images where HeritageId=@HeritageId
union all
select  right(ImageURL, CHARINDEX(',',ImageURL+',')-1),
    STUFF(ImageURL, 1, CHARINDEX(',',ImageURL+','), '')
from Images
where ImageURL > '' and HeritageId=@HeritageId
)
select  ImageURL
from tmp

Answer 1

Your query looks like an attempt to use a recursive CTE to split a string. It that is the case it should look something like this.

;with tmp(ImageURL,Rest) as
 (

select  LEFT(ImageURL, CHARINDEX(',',ImageURL+',')-1),
    STUFF(ImageURL, 1, CHARINDEX(',',ImageURL+','), '')
from Images where HeritageId=@HeritageId
union all
select  LEFT(Rest, CHARINDEX(',',Rest+',')-1),
    STUFF(Rest, 1, CHARINDEX(',',Rest+','), '')
from tmp
where Rest > ''
)
select  ImageURL
from tmp

Use the CTE in the recursive part instead of the table.

Answer 2

Would it be possible/acceptable for you to retrieve them as one string and then use Split(',') to return an array of strings?

Alternately see this question if you wish to use the LINQ-TO-SQL way.

Answer 3

I would suggest using (and marking) the answer suggested by @Mikael, however if your sequence only has 4 values then you can use the PARSENAME function to split on a period.

DECLARE @test TABLE 
(
    [CSVColumn] NVARCHAR(MAX) NOT NULL
)

INSERT INTO @test VALUES ('The PARSENAME function splits on a period.But can only hold.Four.Values - any more and it will return null')
SELECT  PARSENAME([CSVColumn], 4) AS 'Col1', 
        PARSENAME([CSVColumn], 3) AS 'Col2', 
        PARSENAME([CSVColumn], 2) AS 'Col3', 
        PARSENAME([CSVColumn], 1) AS 'Col4'
FROM @test