修改@Aaron Bertrand的功能

CREATE FUNCTION [dbo].[SplitString]
(
    @List NVARCHAR(MAX),
    @Delim VARCHAR(255),
    @Idx int
)
RETURNS NVARCHAR(1000)
AS
BEGIN
    DECLARE @ValueTable TABLE(String NVARCHAR(50), Ind int)
    DECLARE @Value NVARCHAR(50)
    BEGIN
    INSERT INTO @ValueTable
    SELECT Value, idx FROM
        (SELECT [Value], idx = RANK() OVER (ORDER BY n) FROM 
              ( 
                SELECT n = Number, 
                [Value] = LTRIM(RTRIM(SUBSTRING(@List, [Number],
                CHARINDEX(@Delim, @List + @Delim, [Number]) - [Number])))
                FROM    
                        (SELECT Number = ROW_NUMBER() OVER (ORDER BY name)
                         FROM sys.all_objects) AS x
                WHERE Number <= LEN(@List)
                AND SUBSTRING(@Delim + @List, [Number], LEN(@Delim)) = @Delim
              ) AS y
          ) AS R WHERE idx = @Idx
    SET @Value = (SELECT String FROM @ValueTable)
    END
    RETURN @Value
END
GO

    Alter Function dbo.fn_Split
    (
    @Expression nvarchar(max),
    @Delimiter  nvarchar(20) = ',',
    @Qualifier  char(1) = Null
    )
    RETURNS @Results TABLE (id int IDENTITY(1,1), value nvarchar(max))
    AS
    BEGIN
       /* USAGE
            Select * From dbo.fn_Split('apple pear grape banana orange honeydew cantalope 3 2 1 4', ' ', Null)
            Select * From dbo.fn_Split('1,abc,"Doe, John",4', ',', '"')
            Select * From dbo.fn_Split('Hello 0,"&""&&&&', ',', '"')
       */

       -- Declare Variables
       DECLARE
          @X     xml,
          @Temp  nvarchar(max),
          @Temp2 nvarchar(max),
          @Start int,
          @End   int

       -- HTML Encode @Expression
       Select @Expression = (Select @Expression For XML Path(''))

       -- Find all occurences of @Delimiter within @Qualifier and replace with |||***|||
       While PATINDEX('%' + @Qualifier + '%', @Expression) > 0 AND Len(IsNull(@Qualifier, '')) > 0
       BEGIN
          Select
             -- Starting character position of @Qualifier
             @Start = PATINDEX('%' + @Qualifier + '%', @Expression),
             -- @Expression starting at the @Start position
             @Temp = SubString(@Expression, @Start + 1, LEN(@Expression)-@Start+1),
             -- Next position of @Qualifier within @Expression
             @End = PATINDEX('%' + @Qualifier + '%', @Temp) - 1,
             -- The part of Expression found between the @Qualifiers
             @Temp2 = Case When @End < 0 Then @Temp Else Left(@Temp, @End) End,
             -- New @Expression
             @Expression = REPLACE(@Expression,
                                   @Qualifier + @Temp2 + Case When @End < 0 Then '' Else @Qualifier End,
                                   Replace(@Temp2, @Delimiter, '|||***|||')
                           )
       END

       -- Replace all occurences of @Delimiter within @Expression with '</fn_Split>&ltfn_Split>'
       -- And convert it to XML so we can select from it
       SET
          @X = Cast('&ltfn_Split>' +
                    Replace(@Expression, @Delimiter, '</fn_Split>&ltfn_Split>') +
                    '</fn_Split>' as xml)

       -- Insert into our returnable table replacing '|||***|||' back to @Delimiter
       INSERT @Results
       SELECT
          "Value" = LTRIM(RTrim(Replace(C.value('.', 'nvarchar(max)'), '|||***|||', @Delimiter)))
       FROM
          @X.nodes('fn_Split') as X(C)

       -- Return our temp table
       RETURN
    END

CREATE FUNCTION [dbo].[fnSplitString] 
( 
    @string NVARCHAR(MAX), 
    @delimiter CHAR(1) 
) 
RETURNS @output TABLE(splitdata NVARCHAR(MAX) 
) 
BEGIN 
    DECLARE @start INT, @end INT 
    SELECT @start = 1, @end = CHARINDEX(@delimiter, @string) 
    WHILE @start < LEN(@string) + 1 BEGIN 
        IF @end = 0  
            SET @end = LEN(@string) + 1

        INSERT INTO @output (splitdata)  
        VALUES(SUBSTRING(@string, @start, @end - @start)) 
        SET @start = @end + 1 
        SET @end = CHARINDEX(@delimiter, @string, @start)

    END 
    RETURN 
END

并使用它

select *from dbo.fnSplitString('Querying SQL Server','')

下面的示例使用递归CTE

更新18.09.2013

CREATE FUNCTION dbo.SplitStrings_CTE(@List nvarchar(max), @Delimiter nvarchar(1))
RETURNS @returns TABLE (val nvarchar(max), [level] int, PRIMARY KEY CLUSTERED([level]))
AS
BEGIN
;WITH cte AS
 (
  SELECT SUBSTRING(@List, 0, CHARINDEX(@Delimiter,  @List + @Delimiter)) AS val,
         CAST(STUFF(@List + @Delimiter, 1, CHARINDEX(@Delimiter, @List + @Delimiter), '') AS nvarchar(max)) AS stval, 
         1 AS [level]
  UNION ALL
  SELECT SUBSTRING(stval, 0, CHARINDEX(@Delimiter, stval)),
         CAST(STUFF(stval, 1, CHARINDEX(@Delimiter, stval), '') AS nvarchar(max)),
         [level] + 1
  FROM cte
  WHERE stval != ''
  )
  INSERT @returns
  SELECT REPLACE(val, ' ','' ) AS val, [level]
  FROM cte
  WHERE val > ''
  RETURN
END

演示SQLFiddle

我不相信SQL Server有内置的分裂函数，所以除了UDF，我知道的唯一其他答案是劫持PARSENAME函数:

SELECT PARSENAME(REPLACE('Hello John Smith', ' ', '.'), 2) 

PARSENAME接受一个字符串，并根据句点分隔它。它接受一个数字作为第二个参数，该数字指定要返回字符串的哪一部分(从后到前工作)。

SELECT PARSENAME(REPLACE('Hello John Smith', ' ', '.'), 3)  --return Hello

明显的问题是当字符串已经包含句点时。我仍然认为使用UDF是最好的方式……还有其他建议吗?

我使用弗雷德里克的答案，但这在SQL Server 2005中不起作用

我修改了它，我使用select with union all，它可以工作

DECLARE @str varchar(max)
SET @str = 'Hello John Smith how are you'

DECLARE @separator varchar(max)
SET @separator = ' '

DECLARE @Splited table(id int IDENTITY(1,1), item varchar(max))

SET @str = REPLACE(@str, @separator, ''' UNION ALL SELECT ''')
SET @str = ' SELECT  ''' + @str + '''  ' 

INSERT INTO @Splited
EXEC(@str)

SELECT * FROM @Splited

结果集是:

id  item
1   Hello
2   John
3   Smith
4   how
5   are
6   you