如何将逗号分隔的值拆分为列

我有这样的桌子

Value   String
-------------------
1       Cleo, Smith

我想将逗号分隔的字符串分成两列

Value  Name Surname
-------------------
1      Cleo   Smith

我只需要两个固定的额外列

CREATE FUNCTION [dbo].[fn_split_string_to_column] (
    @string NVARCHAR(MAX),
    @delimiter CHAR(1)
    )
RETURNS @out_put TABLE (
    [column_id] INT IDENTITY(1, 1) NOT NULL,
    [value] NVARCHAR(MAX)
    )
AS
BEGIN
    DECLARE @value NVARCHAR(MAX),
        @pos INT = 0,
        @len INT = 0

    SET @string = CASE 
            WHEN RIGHT(@string, 1) != @delimiter
                THEN @string + @delimiter
            ELSE @string
            END

    WHILE CHARINDEX(@delimiter, @string, @pos + 1) > 0
    BEGIN
        SET @len = CHARINDEX(@delimiter, @string, @pos + 1) - @pos
        SET @value = SUBSTRING(@string, @pos, @len)

        INSERT INTO @out_put ([value])
        SELECT LTRIM(RTRIM(@value)) AS [column]

        SET @pos = CHARINDEX(@delimiter, @string, @pos + @len) + 1
    END

    RETURN
END

您的目的可以使用以下查询解决：

Select Value  , Substring(FullName, 1,Charindex(',', FullName)-1) as Name,
Substring(FullName, Charindex(',', FullName)+1, LEN(FullName)) as  Surname
from Table1

sql server中没有现成的Split函数，因此我们需要创建用户定义的函数。

CREATE FUNCTION Split (
      @InputString                  VARCHAR(8000),
      @Delimiter                    VARCHAR(50)
)

RETURNS @Items TABLE (
      Item                          VARCHAR(8000)
)

AS
BEGIN
      IF @Delimiter = ' '
      BEGIN
            SET @Delimiter = ','
            SET @InputString = REPLACE(@InputString, ' ', @Delimiter)
      END

      IF (@Delimiter IS NULL OR @Delimiter = '')
            SET @Delimiter = ','

--INSERT INTO @Items VALUES (@Delimiter) -- Diagnostic
--INSERT INTO @Items VALUES (@InputString) -- Diagnostic

      DECLARE @Item           VARCHAR(8000)
      DECLARE @ItemList       VARCHAR(8000)
      DECLARE @DelimIndex     INT

      SET @ItemList = @InputString
      SET @DelimIndex = CHARINDEX(@Delimiter, @ItemList, 0)
      WHILE (@DelimIndex != 0)
      BEGIN
            SET @Item = SUBSTRING(@ItemList, 0, @DelimIndex)
            INSERT INTO @Items VALUES (@Item)

            -- Set @ItemList = @ItemList minus one less item
            SET @ItemList = SUBSTRING(@ItemList, @DelimIndex+1, LEN(@ItemList)-@DelimIndex)
            SET @DelimIndex = CHARINDEX(@Delimiter, @ItemList, 0)
      END -- End WHILE

      IF @Item IS NOT NULL -- At least one delimiter was encountered in @InputString
      BEGIN
            SET @Item = @ItemList
            INSERT INTO @Items VALUES (@Item)
      END

      -- No delimiters were encountered in @InputString, so just return @InputString
      ELSE INSERT INTO @Items VALUES (@InputString)

      RETURN

END -- End Function
GO

---- Set Permissions
--GRANT SELECT ON Split TO UserRole1
--GRANT SELECT ON Split TO UserRole2
--GO

;WITH Split_Names (Value,Name, xmlname)
AS
(
    SELECT Value,
    Name,
    CONVERT(XML,'<Names><name>'  
    + REPLACE(Name,',', '</name><name>') + '</name></Names>') AS xmlname
      FROM tblnames
)

 SELECT Value,      
 xmlname.value('/Names[1]/name[1]','varchar(100)') AS Name,    
 xmlname.value('/Names[1]/name[2]','varchar(100)') AS Surname
 FROM Split_Names

并检查以下链接以供参考

http://jahaines.blogspot.in/2009/06/converting-delimited-string-of-values.html

xml基本答案简单干净

参考这个

DECLARE @S varchar(max),
        @Split char(1),
        @X xml

SELECT @S = 'ab,cd,ef,gh,ij',
       @Split = ','

SELECT @X = CONVERT(xml,' <root> <myvalue>' +
REPLACE(@S,@Split,'</myvalue> <myvalue>') + '</myvalue>   </root> ')

SELECT  T.c.value('.','varchar(20)'),              --retrieve ALL values at once
  T.c.value('(/root/myvalue)[1]','VARCHAR(20)')  , --retrieve index 1 only, which is the 'ab'
  T.c.value('(/root/myvalue)[2]','VARCHAR(20)')
 FROM @X.nodes('/root/myvalue') T(c)

我觉得这很酷

SELECT value,
    PARSENAME(REPLACE(String,',','.'),2) 'Name' ,
    PARSENAME(REPLACE(String,',','.'),1) 'Sur Name'
FROM table WITH (NOLOCK)

使用交叉申请

select ParsedData.* 
from MyTable mt
cross apply ( select str = mt.String + ',,' ) f1
cross apply ( select p1 = charindex( ',', str ) ) ap1
cross apply ( select p2 = charindex( ',', str, p1 + 1 ) ) ap2
cross apply ( select Nmame = substring( str, 1, p1-1 )                   
                 , Surname = substring( str, p1+1, p2-p1-1 )
          ) ParsedData

有多种解决方法，并且已经提出了许多不同的方法。最简单的方法是使用LEFT/ SUBSTRING和其他字符串函数来获得所需的结果。

样本数据

DECLARE @tbl1 TABLE (Value INT,String VARCHAR(MAX))

INSERT INTO @tbl1 VALUES(1,'Cleo, Smith');
INSERT INTO @tbl1 VALUES(2,'John, Mathew');

使用类似的字符串函数 LEFT

SELECT
    Value,
    LEFT(String,CHARINDEX(',',String)-1) as Fname,
    LTRIM(RIGHT(String,LEN(String) - CHARINDEX(',',String) )) AS Lname
FROM @tbl1

如果字符串中有2个以上的项目，则此方法将失败。在这种情况下，我们可以使用分隔PIVOT符，然后使用或将字符串转换为，XML然后使用.nodes来获取字符串项。XMLaads和bvr在其解决方案中详细介绍了基于解决方案的解决方案。

这个问题的答案使用分割器，所有使用WHILE分割器效率低下。检查此性能比较。最好的分离器之一是DelimitedSplit8KJeff Moden创建的。您可以在此处了解更多信息

分离器 PIVOT

DECLARE @tbl1 TABLE (Value INT,String VARCHAR(MAX))

INSERT INTO @tbl1 VALUES(1,'Cleo, Smith');
INSERT INTO @tbl1 VALUES(2,'John, Mathew');


SELECT t3.Value,[1] as Fname,[2] as Lname
FROM @tbl1 as t1
CROSS APPLY [dbo].[DelimitedSplit8K](String,',') as t2
PIVOT(MAX(Item) FOR ItemNumber IN ([1],[2])) as t3

输出量

Value   Fname   Lname
1   Cleo    Smith
2   John    Mathew

DelimitedSplit8K 杰夫·摩登（Jeff Moden）

CREATE FUNCTION [dbo].[DelimitedSplit8K]
/**********************************************************************************************************************
 Purpose:
 Split a given string at a given delimiter and return a list of the split elements (items).

 Notes:
 1.  Leading a trailing delimiters are treated as if an empty string element were present.
 2.  Consecutive delimiters are treated as if an empty string element were present between them.
 3.  Except when spaces are used as a delimiter, all spaces present in each element are preserved.

 Returns:
 iTVF containing the following:
 ItemNumber = Element position of Item as a BIGINT (not converted to INT to eliminate a CAST)
 Item       = Element value as a VARCHAR(8000)

 Statistics on this function may be found at the following URL:
 http://www.sqlservercentral.com/Forums/Topic1101315-203-4.aspx

 CROSS APPLY Usage Examples and Tests:
--=====================================================================================================================
-- TEST 1:
-- This tests for various possible conditions in a string using a comma as the delimiter.  The expected results are
-- laid out in the comments
--=====================================================================================================================
--===== Conditionally drop the test tables to make reruns easier for testing.
     -- (this is NOT a part of the solution)
     IF OBJECT_ID('tempdb..#JBMTest') IS NOT NULL DROP TABLE #JBMTest
;
--===== Create and populate a test table on the fly (this is NOT a part of the solution).
     -- In the following comments, "b" is a blank and "E" is an element in the left to right order.
     -- Double Quotes are used to encapsulate the output of "Item" so that you can see that all blanks
     -- are preserved no matter where they may appear.
 SELECT *
   INTO #JBMTest
   FROM (                                               --# & type of Return Row(s)
         SELECT  0, NULL                      UNION ALL --1 NULL
         SELECT  1, SPACE(0)                  UNION ALL --1 b (Empty String)
         SELECT  2, SPACE(1)                  UNION ALL --1 b (1 space)
         SELECT  3, SPACE(5)                  UNION ALL --1 b (5 spaces)
         SELECT  4, ','                       UNION ALL --2 b b (both are empty strings)
         SELECT  5, '55555'                   UNION ALL --1 E
         SELECT  6, ',55555'                  UNION ALL --2 b E
         SELECT  7, ',55555,'                 UNION ALL --3 b E b
         SELECT  8, '55555,'                  UNION ALL --2 b B
         SELECT  9, '55555,1'                 UNION ALL --2 E E
         SELECT 10, '1,55555'                 UNION ALL --2 E E
         SELECT 11, '55555,4444,333,22,1'     UNION ALL --5 E E E E E 
         SELECT 12, '55555,4444,,333,22,1'    UNION ALL --6 E E b E E E
         SELECT 13, ',55555,4444,,333,22,1,'  UNION ALL --8 b E E b E E E b
         SELECT 14, ',55555,4444,,,333,22,1,' UNION ALL --9 b E E b b E E E b
         SELECT 15, ' 4444,55555 '            UNION ALL --2 E (w/Leading Space) E (w/Trailing Space)
         SELECT 16, 'This,is,a,test.'                   --E E E E
        ) d (SomeID, SomeValue)
;
--===== Split the CSV column for the whole table using CROSS APPLY (this is the solution)
 SELECT test.SomeID, test.SomeValue, split.ItemNumber, Item = QUOTENAME(split.Item,'"')
   FROM #JBMTest test
  CROSS APPLY dbo.DelimitedSplit8K(test.SomeValue,',') split
;
--=====================================================================================================================
-- TEST 2:
-- This tests for various "alpha" splits and COLLATION using all ASCII characters from 0 to 255 as a delimiter against
-- a given string.  Note that not all of the delimiters will be visible and some will show up as tiny squares because
-- they are "control" characters.  More specifically, this test will show you what happens to various non-accented 
-- letters for your given collation depending on the delimiter you chose.
--=====================================================================================================================
WITH 
cteBuildAllCharacters (String,Delimiter) AS 
(
 SELECT TOP 256 
        'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789',
        CHAR(ROW_NUMBER() OVER (ORDER BY (SELECT NULL))-1)
   FROM master.sys.all_columns
)
 SELECT ASCII_Value = ASCII(c.Delimiter), c.Delimiter, split.ItemNumber, Item = QUOTENAME(split.Item,'"')
   FROM cteBuildAllCharacters c
  CROSS APPLY dbo.DelimitedSplit8K(c.String,c.Delimiter) split
  ORDER BY ASCII_Value, split.ItemNumber
;
-----------------------------------------------------------------------------------------------------------------------
 Other Notes:
 1. Optimized for VARCHAR(8000) or less.  No testing or error reporting for truncation at 8000 characters is done.
 2. Optimized for single character delimiter.  Multi-character delimiters should be resolvedexternally from this 
    function.
 3. Optimized for use with CROSS APPLY.
 4. Does not "trim" elements just in case leading or trailing blanks are intended.
 5. If you don't know how a Tally table can be used to replace loops, please see the following...
    http://www.sqlservercentral.com/articles/T-SQL/62867/
 6. Changing this function to use NVARCHAR(MAX) will cause it to run twice as slow.  It's just the nature of 
    VARCHAR(MAX) whether it fits in-row or not.
 7. Multi-machine testing for the method of using UNPIVOT instead of 10 SELECT/UNION ALLs shows that the UNPIVOT method
    is quite machine dependent and can slow things down quite a bit.
-----------------------------------------------------------------------------------------------------------------------
 Credits:
 This code is the product of many people's efforts including but not limited to the following:
 cteTally concept originally by Iztek Ben Gan and "decimalized" by Lynn Pettis (and others) for a bit of extra speed
 and finally redacted by Jeff Moden for a different slant on readability and compactness. Hat's off to Paul White for
 his simple explanations of CROSS APPLY and for his detailed testing efforts. Last but not least, thanks to
 Ron "BitBucket" McCullough and Wayne Sheffield for their extreme performance testing across multiple machines and
 versions of SQL Server.  The latest improvement brought an additional 15-20% improvement over Rev 05.  Special thanks
 to "Nadrek" and "peter-757102" (aka Peter de Heer) for bringing such improvements to light.  Nadrek's original
 improvement brought about a 10% performance gain and Peter followed that up with the content of Rev 07.  

 I also thank whoever wrote the first article I ever saw on "numbers tables" which is located at the following URL
 and to Adam Machanic for leading me to it many years ago.
 http://sqlserver2000.databases.aspfaq.com/why-should-i-consider-using-an-auxiliary-numbers-table.html
-----------------------------------------------------------------------------------------------------------------------
 Revision History:
 Rev 00 - 20 Jan 2010 - Concept for inline cteTally: Lynn Pettis and others.
                        Redaction/Implementation: Jeff Moden 
        - Base 10 redaction and reduction for CTE.  (Total rewrite)

 Rev 01 - 13 Mar 2010 - Jeff Moden
        - Removed one additional concatenation and one subtraction from the SUBSTRING in the SELECT List for that tiny
          bit of extra speed.

 Rev 02 - 14 Apr 2010 - Jeff Moden
        - No code changes.  Added CROSS APPLY usage example to the header, some additional credits, and extra 
          documentation.

 Rev 03 - 18 Apr 2010 - Jeff Moden
        - No code changes.  Added notes 7, 8, and 9 about certain "optimizations" that don't actually work for this
          type of function.

 Rev 04 - 29 Jun 2010 - Jeff Moden
        - Added WITH SCHEMABINDING thanks to a note by Paul White.  This prevents an unnecessary "Table Spool" when the
          function is used in an UPDATE statement even though the function makes no external references.

 Rev 05 - 02 Apr 2011 - Jeff Moden
        - Rewritten for extreme performance improvement especially for larger strings approaching the 8K boundary and
          for strings that have wider elements.  The redaction of this code involved removing ALL concatenation of 
          delimiters, optimization of the maximum "N" value by using TOP instead of including it in the WHERE clause,
          and the reduction of all previous calculations (thanks to the switch to a "zero based" cteTally) to just one 
          instance of one add and one instance of a subtract. The length calculation for the final element (not 
          followed by a delimiter) in the string to be split has been greatly simplified by using the ISNULL/NULLIF 
          combination to determine when the CHARINDEX returned a 0 which indicates there are no more delimiters to be
          had or to start with. Depending on the width of the elements, this code is between 4 and 8 times faster on a
          single CPU box than the original code especially near the 8K boundary.
        - Modified comments to include more sanity checks on the usage example, etc.
        - Removed "other" notes 8 and 9 as they were no longer applicable.

 Rev 06 - 12 Apr 2011 - Jeff Moden
        - Based on a suggestion by Ron "Bitbucket" McCullough, additional test rows were added to the sample code and
          the code was changed to encapsulate the output in pipes so that spaces and empty strings could be perceived 
          in the output.  The first "Notes" section was added.  Finally, an extra test was added to the comments above.

 Rev 07 - 06 May 2011 - Peter de Heer, a further 15-20% performance enhancement has been discovered and incorporated 
          into this code which also eliminated the need for a "zero" position in the cteTally table. 
**********************************************************************************************************************/
--===== Define I/O parameters
        (@pString VARCHAR(8000), @pDelimiter CHAR(1))
RETURNS TABLE WITH SCHEMABINDING AS
 RETURN
--===== "Inline" CTE Driven "Tally Table" produces values from 0 up to 10,000...
     -- enough to cover NVARCHAR(4000)
  WITH E1(N) AS (
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
                ),                          --10E+1 or 10 rows
       E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
       E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
 cteTally(N) AS (--==== This provides the "base" CTE and limits the number of rows right up front
                     -- for both a performance gain and prevention of accidental "overruns"
                 SELECT TOP (ISNULL(DATALENGTH(@pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
                ),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
                 SELECT 1 UNION ALL
                 SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(@pString,t.N,1) = @pDelimiter
                ),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
                 SELECT s.N1,
                        ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,8000)
                   FROM cteStart s
                )
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
 SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
        Item       = SUBSTRING(@pString, l.N1, l.L1)
   FROM cteLen l
;

GO

尝试此操作（将“”的实例更改为“，”或您要使用的任何定界符）

CREATE FUNCTION dbo.Wordparser
(
  @multiwordstring VARCHAR(255),
  @wordnumber      NUMERIC
)
returns VARCHAR(255)
AS
  BEGIN
      DECLARE @remainingstring VARCHAR(255)
      SET @remainingstring=@multiwordstring

      DECLARE @numberofwords NUMERIC
      SET @numberofwords=(LEN(@remainingstring) - LEN(REPLACE(@remainingstring, ' ', '')) + 1)

      DECLARE @word VARCHAR(50)
      DECLARE @parsedwords TABLE
      (
         line NUMERIC IDENTITY(1, 1),
         word VARCHAR(255)
      )

      WHILE @numberofwords > 1
        BEGIN
            SET @word=LEFT(@remainingstring, CHARINDEX(' ', @remainingstring) - 1)

            INSERT INTO @parsedwords(word)
            SELECT @word

            SET @remainingstring= REPLACE(@remainingstring, Concat(@word, ' '), '')
            SET @numberofwords=(LEN(@remainingstring) - LEN(REPLACE(@remainingstring, ' ', '')) + 1)

            IF @numberofwords = 1
              BREAK

            ELSE
              CONTINUE
        END

      IF @numberofwords = 1
        SELECT @word = @remainingstring
      INSERT INTO @parsedwords(word)
      SELECT @word

      RETURN
        (SELECT word
         FROM   @parsedwords
         WHERE  line = @wordnumber)

  END

用法示例：

SELECT dbo.Wordparser(COLUMN, 1),
       dbo.Wordparser(COLUMN, 2),
       dbo.Wordparser(COLUMN, 3)
FROM   TABLE

使用SQL Server 2016，我们可以使用string_split完成此操作：

create table commasep (
 id int identity(1,1)
 ,string nvarchar(100) )

insert into commasep (string) values ('John, Adam'), ('test1,test2,test3')

select id, [value] as String from commasep 
 cross apply string_split(string,',')

我认为PARSENAME是用于此示例的简洁函数，如本文所述：http : //www.sqlshack.com/parsing-and-rotating-delimited-data-in-sql-server-2012/

PARSENAME函数在逻辑上设计为解析由四部分组成的对象名称。PARSENAME的好处在于它不仅限于解析SQL Server的四部分对象名称-它还将解析由点分隔的任何函数或字符串数​​据。

第一个参数是要解析的对象，第二个参数是要返回的对象片段的整数值。本文讨论的是解析和旋转定界数据（公司电话号码），但也可用于解析名称/姓氏数据。

例：

USE COMPANY;
SELECT PARSENAME('Whatever.you.want.parsed',3) AS 'ReturnValue';

本文还介绍了如何使用称为“ replaceChars”的公用表表达式（CTE）对分隔符替换的值运行PARSENAME。CTE对于返回临时视图或结果集很有用。

之后，使用UNPIVOT函数将某些列转换为行；SUBSTRING和CHARINDEX函数已用于清除数据中的不一致，最后使用了LAG函数（SQL Server 2012的新增功能），因为它允许引用以前的记录。

SELECT id,
       Substring(NAME, 0, Charindex(',', NAME))             AS firstname,
       Substring(NAME, Charindex(',', NAME), Len(NAME) + 1) AS lastname
FROM   spilt  

我们可以这样创建一个函数

CREATE Function [dbo].[fn_CSVToTable] 
(
    @CSVList Varchar(max)
)
RETURNS @Table TABLE (ColumnData VARCHAR(100))
AS
BEGIN
    IF RIGHT(@CSVList, 1) <> ','
    SELECT @CSVList = @CSVList + ','

    DECLARE @Pos    BIGINT,
            @OldPos BIGINT
    SELECT  @Pos    = 1,
            @OldPos = 1

    WHILE   @Pos < LEN(@CSVList)
        BEGIN
            SELECT  @Pos = CHARINDEX(',', @CSVList, @OldPos)
            INSERT INTO @Table
            SELECT  LTRIM(RTRIM(SUBSTRING(@CSVList, @OldPos, @Pos - @OldPos))) Col001

            SELECT  @OldPos = @Pos + 1
        END

    RETURN
END

然后，我们可以使用SELECT语句将CSV值分成相应的列

我认为以下功能将为您工作：

您必须先在SQL中创建一个函数。像这样

CREATE FUNCTION [dbo].[fn_split](
@str VARCHAR(MAX),
@delimiter CHAR(1)
)
RETURNS @returnTable TABLE (idx INT PRIMARY KEY IDENTITY, item VARCHAR(8000))
AS
BEGIN
DECLARE @pos INT
SELECT @str = @str + @delimiter
WHILE LEN(@str) > 0 
    BEGIN
        SELECT @pos = CHARINDEX(@delimiter,@str)
        IF @pos = 1
            INSERT @returnTable (item)
                VALUES (NULL)
        ELSE
            INSERT @returnTable (item)
                VALUES (SUBSTRING(@str, 1, @pos-1))
        SELECT @str = SUBSTRING(@str, @pos+1, LEN(@str)-@pos)       
    END
RETURN
END

您可以像下面这样调用此函数：

select * from fn_split('1,24,5',',')

实现方式：

Declare @test TABLE (
ID VARCHAR(200),
Data VARCHAR(200)
)

insert into @test 
(ID, Data)
Values
('1','Cleo,Smith')


insert into @test 
(ID, Data)
Values
('2','Paul,Grim')

select ID,
(select item from fn_split(Data,',') where idx in (1)) as Name ,
(select item from fn_split(Data,',') where idx in (2)) as Surname
 from @test

结果将如下所示：

您可以使用表值函数STRING_SPLIT，该函数仅在兼容级别130下可用。如果您的数据库兼容级别低于130，则SQL Server将无法找到并执行该STRING_SPLIT函数。您可以使用以下命令更改数据库的兼容性级别：

ALTER DATABASE DatabaseName SET COMPATIBILITY_LEVEL = 130

句法

SELECT * FROM STRING_SPLIT ( string, separator )

在这里查看文档

使用Parsename（）函数

with cte as(
    select 'Aria,Karimi' as FullName
    Union
    select 'Joe,Karimi' as FullName
    Union
    select 'Bab,Karimi' as FullName
)

SELECT PARSENAME(REPLACE(FullName,',','.'),2) as Name, 
       PARSENAME(REPLACE(FullName,',','.'),1) as Family
    FROM cte

结果

Name    Family
-----   ------
Aria    Karimi
Bab     Karimi
Joe     Karimi

试试这个：

declare @csv varchar(100) ='aaa,bb,csda,daass';
set @csv = @csv+',';

with cte as
(
    select SUBSTRING(@csv,1,charindex(',',@csv,1)-1) as val, SUBSTRING(@csv,charindex(',',@csv,1)+1,len(@csv)) as rem 
    UNION ALL
    select SUBSTRING(a.rem,1,charindex(',',a.rem,1)-1)as val, SUBSTRING(a.rem,charindex(',',a.rem,1)+1,len(A.rem)) 
    from cte a where LEN(a.rem)>=1
    ) select val from cte

我遇到了类似的问题，但是却很复杂，因为这是我发现的有关该问题的第一个线索，所以我决定发表我的发现。我知道这是解决一个简单问题的复杂解决方案，但我希望我能帮助其他寻求该解决方案的人。我不得不拆分一个包含5个数字的字符串（列名：levelsFeed），并在单独的列中显示每个数字。例如：8,1,2,2,2应显示为：

1  2  3  4  5
-------------
8  1  2  2  2

解决方案1：使用XML函数：此解决方案是迄今为止最慢的解决方案

SELECT Distinct FeedbackID, 
, S.a.value('(/H/r)[1]', 'INT') AS level1
, S.a.value('(/H/r)[2]', 'INT') AS level2
, S.a.value('(/H/r)[3]', 'INT') AS level3
, S.a.value('(/H/r)[4]', 'INT') AS level4
, S.a.value('(/H/r)[5]', 'INT') AS level5
FROM (            
    SELECT *,CAST (N'<H><r>' + REPLACE(levelsFeed, ',', '</r><r>')  + '</r> </H>' AS XML) AS [vals]
    FROM Feedbacks 
)  as d
CROSS APPLY d.[vals].nodes('/H/r') S(a)

解决方案2：使用分割功能和旋转。（split函数将字符串拆分为具有列名称Data的行）

SELECT FeedbackID, [1],[2],[3],[4],[5]
FROM (
    SELECT *, ROW_NUMBER() OVER (PARTITION BY feedbackID ORDER BY (SELECT  null)) as rn 
FROM (
    SELECT FeedbackID, levelsFeed
    FROM Feedbacks 
) as a
CROSS APPLY dbo.Split(levelsFeed, ',')
) as SourceTable
PIVOT
(
    MAX(data)
    FOR rn IN ([1],[2],[3],[4],[5])
)as pivotTable

解决方案3：使用字符串操作功能-比解决方案2快一点点

SELECT FeedbackID,
SUBSTRING(levelsFeed,0,CHARINDEX(',',levelsFeed)) AS level1,
PARSENAME(REPLACE(SUBSTRING(levelsFeed,CHARINDEX(',',levelsFeed)+1,LEN(levelsFeed)),',','.'),4) AS level2,
PARSENAME(REPLACE(SUBSTRING(levelsFeed,CHARINDEX(',',levelsFeed)+1,LEN(levelsFeed)),',','.'),3) AS level3,
PARSENAME(REPLACE(SUBSTRING(levelsFeed,CHARINDEX(',',levelsFeed)+1,LEN(levelsFeed)),',','.'),2) AS level4,
PARSENAME(REPLACE(SUBSTRING(levelsFeed,CHARINDEX(',',levelsFeed)+1,LEN(levelsFeed)),',','.'),1) AS level5
FROM Feedbacks

由于levelsFeed包含5个字符串值，因此我需要为第一个字符串使用子字符串功能。

我希望我的解决方案可以帮助其他人找到更复杂的拆分为列方法

使用instring函数:)

select Value, 
       substring(String,1,instr(String," ") -1) Fname,  
       substring(String,instr(String,",") +1) Sname 
from tablename;

使用了两个函数：
1. substring(string, position, length) ==>从正数返回字符串到长度
2。instr(string,pattern)==>返回模式的位置。

如果我们在子字符串中不提供length参数，它将返回到字符串末尾

此功能最快：

CREATE FUNCTION dbo.F_ExtractSubString
(
  @String VARCHAR(MAX),
  @NroSubString INT,
  @Separator VARCHAR(5)
)
RETURNS VARCHAR(MAX) AS
BEGIN
    DECLARE @St INT = 0, @End INT = 0, @Ret VARCHAR(MAX)
    SET @String = @String + @Separator
    WHILE CHARINDEX(@Separator, @String, @End + 1) > 0 AND @NroSubString > 0
    BEGIN
        SET @St = @End + 1
        SET @End = CHARINDEX(@Separator, @String, @End + 1)
        SET @NroSubString = @NroSubString - 1
    END
    IF @NroSubString > 0
        SET @Ret = ''
    ELSE
        SET @Ret = SUBSTRING(@String, @St, @End - @St)
    RETURN @Ret
END
GO

用法示例：

SELECT dbo.F_ExtractSubString(COLUMN, 1, ', '),
       dbo.F_ExtractSubString(COLUMN, 2, ', '),
       dbo.F_ExtractSubString(COLUMN, 3, ', ')
FROM   TABLE

这对我有用

CREATE FUNCTION [dbo].[SplitString](
    @delimited NVARCHAR(MAX),
    @delimiter NVARCHAR(100)
) RETURNS @t TABLE ( val NVARCHAR(MAX))
AS
BEGIN
    DECLARE @xml XML
    SET @xml = N'<t>' + REPLACE(@delimited,@delimiter,'</t><t>') + '</t>'
    INSERT INTO @t(val)
    SELECT  r.value('.','varchar(MAX)') as item
    FROM  @xml.nodes('/t') as records(r)
    RETURN
END

mytable：

Value  ColOne
--------------------
1      Cleo, Smith

如果没有太多的列，则以下内容应该起作用

ALTER TABLE mytable ADD ColTwo nvarchar(256);
UPDATE mytable SET ColTwo = LEFT(ColOne, Charindex(',', ColOne) - 1);
--'Cleo' = LEFT('Cleo, Smith', Charindex(',', 'Cleo, Smith') - 1)
UPDATE mytable SET ColTwo = REPLACE(ColOne, ColTwo + ',', '');
--' Smith' = REPLACE('Cleo, Smith', 'Cleo' + ',')
UPDATE mytable SET ColOne = REPLACE(ColOne, ',' + ColTwo, ''), ColTwo = LTRIM(ColTwo);
--'Cleo' = REPLACE('Cleo, Smith', ',' + ' Smith', '') 

结果：

Value  ColOne ColTwo
--------------------
1      Cleo   Smith

这很简单，您可以通过以下查询进行查询：

DECLARE @str NVARCHAR(MAX)='ControlID_05436b78-04ba-9667-fa01-9ff8c1b7c235,3'
SELECT LEFT(@str, CHARINDEX(',',@str)-1),RIGHT(@str,LEN(@str)-(CHARINDEX(',',@str)))

DECLARE @INPUT VARCHAR (MAX)='N,A,R,E,N,D,R,A'
DECLARE @ELIMINATE_CHAR CHAR (1)=','
DECLARE @L_START INT=1
DECLARE @L_END INT=(SELECT LEN (@INPUT))
DECLARE @OUTPUT CHAR (1)

WHILE @L_START <=@L_END
BEGIN
    SET @OUTPUT=(SUBSTRING (@INPUT,@L_START,1))
    IF @OUTPUT!=@ELIMINATE_CHAR
    BEGIN
        PRINT @OUTPUT
    END
    SET @L_START=@L_START+1
END

您可能会发现“ SQL用户定义函数”中解析定界字符串的解决方案很有用（来自The Code Project））。

这是此页面的代码部分：

CREATE FUNCTION [fn_ParseText2Table]
  (@p_SourceText VARCHAR(MAX)
  ,@p_Delimeter VARCHAR(100)=',' --default to comma delimited.
  )
 RETURNS @retTable
  TABLE([Position] INT IDENTITY(1,1)
   ,[Int_Value] INT
   ,[Num_Value] NUMERIC(18,3)
   ,[Txt_Value] VARCHAR(MAX)
   ,[Date_value] DATETIME
   )
AS
/*
********************************************************************************
Purpose: Parse values from a delimited string
  & return the result as an indexed table
Copyright 1996, 1997, 2000, 2003 Clayton Groom (<A href="mailto:Clayton_Groom@hotmail.com">Clayton_Groom@hotmail.com</A>)
Posted to the public domain Aug, 2004
2003-06-17 Rewritten as SQL 2000 function.
 Reworked to allow for delimiters > 1 character in length
 and to convert Text values to numbers
2016-04-05 Added logic for date values based on "new" ISDATE() function, Updated to use XML approach, which is more efficient.
********************************************************************************
*/


BEGIN
 DECLARE @w_xml xml;
 SET @w_xml = N'<root><i>' + replace(@p_SourceText, @p_Delimeter,'</i><i>') + '</i></root>';


 INSERT INTO @retTable
     ([Int_Value]
    , [Num_Value]
    , [Txt_Value]
    , [Date_value]
     )
     SELECT CASE
       WHEN ISNUMERIC([i].value('.', 'VARCHAR(MAX)')) = 1
       THEN CAST(CAST([i].value('.', 'VARCHAR(MAX)') AS NUMERIC) AS INT)
      END AS [Int_Value]
    , CASE
       WHEN ISNUMERIC([i].value('.', 'VARCHAR(MAX)')) = 1
       THEN CAST([i].value('.', 'VARCHAR(MAX)') AS NUMERIC(18, 3))
      END AS [Num_Value]
    , [i].value('.', 'VARCHAR(MAX)') AS [txt_Value]
    , CASE
       WHEN ISDATE([i].value('.', 'VARCHAR(MAX)')) = 1
       THEN CAST([i].value('.', 'VARCHAR(MAX)') AS DATETIME)
      END AS [Num_Value]
     FROM @w_xml.nodes('//root/i') AS [Items]([i]);
 RETURN;
END;
GO

ALTER function get_occurance_index(@delimiter varchar(1),@occurence int,@String varchar(100))
returns int
AS Begin
--Declare @delimiter varchar(1)=',',@occurence int=2,@String varchar(100)='a,b,c'
Declare @result int
 ;with T as (
    select 1 Rno,0 as row, charindex(@delimiter, @String) pos,@String st
    union all
    select Rno+1,pos + 1, charindex(@delimiter, @String, pos + 1), @String
    from T
    where pos > 0
)
select  @result=pos 
from T 
where pos > 0   and rno = @occurence 
return isnull(@result,0)
ENd


declare @data as table (data varchar(100))
insert into @data values('1,2,3') 
insert into @data values('aaa,bbbbb,cccc') 
select top  3 Substring (data,0,dbo.get_occurance_index( ',',1,data)) ,--First Record always starts with 0
Substring (data,dbo.get_occurance_index( ',',1,data)+1,dbo.get_occurance_index( ',',2,data)-dbo.get_occurance_index( ',',1,data)-1) ,
Substring (data,dbo.get_occurance_index( ',',2,data)+1,len(data)) , -- Last record cant be more than len of actual data
data 
From @data 

我发现如上所述使用PARSENAME会导致任何带有句点的名称都为空。

因此，如果名称中有首字母或标题，后跟一个点，则它们将返回NULL。

我发现这对我有用：

SELECT 
REPLACE(SUBSTRING(FullName, 1,CHARINDEX(',', FullName)), ',','') as Name,
REPLACE(SUBSTRING(FullName, CHARINDEX(',', FullName), LEN(FullName)), ',', '') as Surname
FROM Table1

select distinct modelFileId,F4.*
from contract
cross apply (select XmlList=convert(xml, '<x>'+replace(modelFileId,';','</x><x>')+'</x>').query('.')) F2
cross apply (select mfid1=XmlNode.value('/x[1]','varchar(512)')
,mfid2=XmlNode.value('/x[2]','varchar(512)')
,mfid3=XmlNode.value('/x[3]','varchar(512)')
,mfid4=XmlNode.value('/x[4]','varchar(512)') from XmlList.nodes('x') F3(XmlNode)) F4
where modelFileId like '%;%'
order by modelFileId

Select distinct PROJ_UID,PROJ_NAME,RES_UID from E2E_ProjectWiseTimesheetActuals
where   CHARINDEX(','+cast(PROJ_UID as varchar(8000))+',', @params) > 0 and  CHARINDEX(','+cast(RES_UID as varchar(8000))+',', @res) > 0

我重新编写了上面的答案，并使它变得更好：

CREATE FUNCTION [dbo].[CSVParser]
(
  @s        VARCHAR(255),
  @idx      NUMERIC
)
RETURNS VARCHAR(12)
BEGIN
    DECLARE @comma int
    SET @comma = CHARINDEX(',', @s)
    WHILE 1=1
    BEGIN
        IF @comma=0
            IF @idx=1
                RETURN @s
            ELSE
                RETURN ''

        IF @idx=1
        BEGIN
            DECLARE @word VARCHAR(12)
            SET @word=LEFT(@s, @comma - 1)
            RETURN @word
        END

        SET @s = RIGHT(@s,LEN(@s)-@comma)
        SET @comma = CHARINDEX(',', @s)
        SET @idx = @idx - 1
    END
    RETURN 'not used'
END

用法示例：

SELECT dbo.CSVParser(COLUMN, 1),
       dbo.CSVParser(COLUMN, 2),
       dbo.CSVParser(COLUMN, 3)
FROM   TABLE

CREATE FUNCTION [dbo].[fnSplit](@sInputList VARCHAR(8000), @sDelimiter VARCHAR(8000) = ',')
RETURNS @List TABLE (item VARCHAR(8000))
BEGIN

    DECLARE @sItem VARCHAR(8000)
    WHILE CHARINDEX(@sDelimiter, @sInputList, 0) <> 0
    BEGIN

        SELECT @sItem = RTRIM(LTRIM(SUBSTRING(@sInputList, 1, CHARINDEX(@sDelimiter, @sInputList,0) - 1))),
               @sInputList = RTRIM(LTRIM(SUBSTRING(@sInputList, CHARINDEX(@sDelimiter, @sInputList, 0) + LEN(@sDelimiter),LEN(@sInputList))))

        -- Indexes to keep the position of searching
        IF LEN(@sItem) > 0

        INSERT INTO @List SELECT @sItem

    END

    IF LEN(@sInputList) > 0
    BEGIN

        INSERT INTO @List SELECT @sInputList -- Put the last item in

    END

    RETURN

END