T-SQL 中的拆分函数等效吗？
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Split function equivalent in T-SQL?
提问by jinsungy
I'm looking to split '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15...' (comma delimited) into a table or table variable.
我希望将 '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15...'（逗号分隔）拆分为表或表变量.
Does anyone have a function that returns each one in a row?
有没有人有一个函数可以连续返回每个？
采纳答案by XOR
Here is somewhat old-fashioned solution:
这是有点老式的解决方案：
/*
Splits string into parts delimitered with specified character.
*/
CREATE FUNCTION [dbo].[SDF_SplitString]
(
@sString nvarchar(2048),
@cDelimiter nchar(1)
)
RETURNS @tParts TABLE ( part nvarchar(2048) )
AS
BEGIN
if @sString is null return
declare @iStart int,
@iPos int
if substring( @sString, 1, 1 ) = @cDelimiter
begin
set @iStart = 2
insert into @tParts
values( null )
end
else
set @iStart = 1
while 1=1
begin
set @iPos = charindex( @cDelimiter, @sString, @iStart )
if @iPos = 0
set @iPos = len( @sString )+1
if @iPos - @iStart > 0
insert into @tParts
values ( substring( @sString, @iStart, @iPos-@iStart ))
else
insert into @tParts
values( null )
set @iStart = @iPos+1
if @iStart > len( @sString )
break
end
RETURN
END
In SQL Server 2008 you can achieve the same with .NET code. Maybe it would work faster, but definitely this approach is easier to manage.
在 SQL Server 2008 中，您可以使用 .NET 代码实现相同的效果。也许它会工作得更快，但这种方法肯定更容易管理。
回答by priyanka.sarkar
Try this
尝试这个
DECLARE @xml xml, @str varchar(100), @delimiter varchar(10)
SET @str = '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15'
SET @delimiter = ','
SET @xml = cast(('<X>'+replace(@str, @delimiter, '</X><X>')+'</X>') as xml)
SELECT C.value('.', 'varchar(10)') as value FROM @xml.nodes('X') as X(C)
OR
或者
DECLARE @str varchar(100), @delimiter varchar(10)
SET @str = '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15'
SET @delimiter = ','
;WITH cte AS
(
SELECT 0 a, 1 b
UNION ALL
SELECT b, CHARINDEX(@delimiter, @str, b) + LEN(@delimiter)
FROM CTE
WHERE b > a
)
SELECT SUBSTRING(@str, a,
CASE WHEN b > LEN(@delimiter)
THEN b - a - LEN(@delimiter)
ELSE LEN(@str) - a + 1 END) value
FROM cte WHERE a > 0
Many more ways of doing the same is here How to split comma delimited string?
这里有更多的方法来做同样的事情如何拆分逗号分隔的字符串？
回答by Martin Smith
You've tagged this SQL Server 2008 but future visitors to this question (using SQL Server 2016+) will likely want to know about STRING_SPLIT.
您已标记此 SQL Server 2008，但此问题的未来访问者（使用 SQL Server 2016+）可能想了解STRING_SPLIT.
With this new builtin function you can now just use
使用这个新的内置函数，您现在可以使用
SELECT TRY_CAST(value AS INT)
FROM STRING_SPLIT ('1,2,3,4,5,6,7,8,9,10,11,12,13,14,15', ',')
Some restrictions of this function and some promising results of performance testing are in this blog post by Aaron Bertrand.
此功能的一些限制以及性能测试的一些有希望的结果在Aaron Bertrand 的这篇博文中。
回答by Todd
This is most like .NET, for those of you who are familiar with that function:
对于熟悉该功能的人来说，这与 .NET 最相似：
CREATE FUNCTION dbo.[String.Split]
(
@Text VARCHAR(MAX),
@Delimiter VARCHAR(100),
@Index INT
)
RETURNS VARCHAR(MAX)
AS BEGIN
DECLARE @A TABLE (ID INT IDENTITY, V VARCHAR(MAX));
DECLARE @R VARCHAR(MAX);
WITH CTE AS
(
SELECT 0 A, 1 B
UNION ALL
SELECT B, CONVERT(INT,CHARINDEX(@Delimiter, @Text, B) + LEN(@Delimiter))
FROM CTE
WHERE B > A
)
INSERT @A(V)
SELECT SUBSTRING(@Text,A,CASE WHEN B > LEN(@Delimiter) THEN B-A-LEN(@Delimiter) ELSE LEN(@Text) - A + 1 END) VALUE
FROM CTE WHERE A >0
SELECT @R
= V
FROM @A
WHERE ID = @Index + 1
RETURN @R
END
SELECT dbo.[String.Split]('121,2,3,0',',',1) -- gives '2'
回答by Sivaganesh Tamilvendhan
here is the split function that u asked
这是你问的拆分功能
CREATE FUNCTION [dbo].[split](
@delimited NVARCHAR(MAX),
@delimiter NVARCHAR(100)
) RETURNS @t TABLE (id INT IDENTITY(1,1), 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
execute the function like this
像这样执行函数
select * from dbo.split('1,2,3,4,5,6,7,8,9,10,11,12,13,14,15',',')
回答by Mihai Bejenariu
DECLARE
@InputString NVARCHAR(MAX) = 'token1,token2,token3,token4,token5'
, @delimiter varchar(10) = ','
DECLARE @xml AS XML = CAST(('<X>'+REPLACE(@InputString,@delimiter ,'</X><X>')+'</X>') AS XML)
SELECT C.value('.', 'varchar(10)') AS value
FROM @xml.nodes('X') as X(C)
Source of this response: http://sqlhint.com/sqlserver/how-to/best-split-function-tsql-delimited
此响应的来源：http: //sqlhint.com/sqlserver/how-to/best-split-function-tsql-delimited
回答by Reza
CREATE FUNCTION Split
(
@delimited nvarchar(max),
@delimiter nvarchar(100)
) RETURNS @t TABLE
(
-- Id column can be commented out, not required for sql splitting string
id int identity(1,1), -- I use this column for numbering splitted parts
val nvarchar(max)
)
AS
BEGIN
declare @xml xml
set @xml = N'<root><r>' + replace(@delimited,@delimiter,'</r><r>') + '</r></root>'
insert into @t(val)
select
r.value('.','varchar(max)') as item
from @xml.nodes('//root/r') as records(r)
RETURN
END
GO
usage
用法
Select * from dbo.Split(N'1,2,3,4,6',',')
回答by Micha? Turczyn
This simple CTE will give what's needed:
这个简单的 CTE 将提供所需的内容：
DECLARE @csv varchar(max) = '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15';
--append comma to the list for CTE to work correctly
SET @csv = @csv + ',';
--remove double commas (empty entries)
SET @csv = replace(@csv, ',,', ',');
WITH CteCsv AS (
SELECT CHARINDEX(',', @csv) idx, SUBSTRING(@csv, 1, CHARINDEX(',', @csv) - 1) [Value]
UNION ALL
SELECT CHARINDEX(',', @csv, idx + 1), SUBSTRING(@csv, idx + 1, CHARINDEX(',', @csv, idx + 1) - idx - 1) FROM CteCsv
WHERE CHARINDEX(',', @csv, idx + 1) > 0
)
SELECT [Value] FROM CteCsv
回答by Irawan Soetomo
I am tempted to squeeze in my favourite solution. The resulting table will consist of 2 columns: PosIdx for position of the found integer; and Value in integer.
我很想挤进我最喜欢的解决方案。结果表将包含 2 列： PosIdx 表示找到的整数的位置；和整数值。
create function FnSplitToTableInt
(
@param nvarchar(4000)
)
returns table as
return
with Numbers(Number) as
(
select 1
union all
select Number + 1 from Numbers where Number < 4000
),
Found as
(
select
Number as PosIdx,
convert(int, ltrim(rtrim(convert(nvarchar(4000),
substring(@param, Number,
charindex(N',' collate Latin1_General_BIN,
@param + N',', Number) - Number))))) as Value
from
Numbers
where
Number <= len(@param)
and substring(N',' + @param, Number, 1) = N',' collate Latin1_General_BIN
)
select
PosIdx,
case when isnumeric(Value) = 1
then convert(int, Value)
else convert(int, null) end as Value
from
Found
It works by using recursive CTE as the list of positions, from 1 to 100 by default. If you need to work with string longer than 100, simply call this function using 'option (maxrecursion 4000)' like the following:
它通过使用递归 CTE 作为位置列表来工作，默认情况下从 1 到 100。如果您需要处理长度超过 100 的字符串，只需使用“option (maxrecursion 4000)”调用此函数，如下所示：
select * from FnSplitToTableInt
(
'9, 8, 7, 6, 5, 4, 3, 2, 1, 0, ' +
'9, 8, 7, 6, 5, 4, 3, 2, 1, 0, ' +
'9, 8, 7, 6, 5, 4, 3, 2, 1, 0, ' +
'9, 8, 7, 6, 5, 4, 3, 2, 1, 0, ' +
'9, 8, 7, 6, 5, 4, 3, 2, 1, 0'
)
option (maxrecursion 4000)
回答by Scormer
This is another version which really does not have any restrictions (e.g.: special chars when using xml approach, number of records in CTE approach) and it runs much faster based on a test on 10M+ records with source string average length of 4000. Hope this could help.
这是另一个版本，它确实没有任何限制（例如：使用 xml 方法时的特殊字符，CTE 方法中的记录数）并且基于对源字符串平均长度为 4000 的 10M+ 记录的测试，它运行得更快。希望如此有帮助。
Create function [dbo].[udf_split] (
@ListString nvarchar(max),
@Delimiter nvarchar(1000),
@IncludeEmpty bit)
Returns @ListTable TABLE (ID int, ListValue nvarchar(1000))
AS
BEGIN
Declare @CurrentPosition int, @NextPosition int, @Item nvarchar(max), @ID int, @L int
Select @ID = 1,
@L = len(replace(@Delimiter,' ','^')),
@ListString = @ListString + @Delimiter,
@CurrentPosition = 1
Select @NextPosition = Charindex(@Delimiter, @ListString, @CurrentPosition)
While @NextPosition > 0 Begin
Set @Item = LTRIM(RTRIM(SUBSTRING(@ListString, @CurrentPosition, @NextPosition-@CurrentPosition)))
If @IncludeEmpty=1 or LEN(@Item)>0 Begin
Insert Into @ListTable (ID, ListValue) Values (@ID, @Item)
Set @ID = @ID+1
End
Set @CurrentPosition = @NextPosition+@L
Set @NextPosition = Charindex(@Delimiter, @ListString, @CurrentPosition)
End
RETURN
END
