我正在尝试确定VARCHAR(3000)
列中的单词频率。我不确定这是否是最好的数据类型,但表格创建不在手。无论如何,我一直在使用以下函数(取自here)来分割字符串直到这一点:
CREATE FUNCTION dbo.Split
(
@RowData nvarchar(2000),
@SplitOn nvarchar(5)
)
RETURNS @RtnValue table
(
Id int identity(1,1),
Data nvarchar(100)
)
AS
BEGIN
Declare @Cnt int
Set @Cnt = 1
While (Charindex(@SplitOn,@RowData)>0)
Begin
Insert Into @RtnValue (data)
Select
Data = ltrim(rtrim(Substring(@RowData,1,Charindex(@SplitOn,@RowData)-1)))
Set @RowData = Substring(@RowData,Charindex(@SplitOn,@RowData)+1,len(@RowData))
Set @Cnt = @Cnt + 1
End
Insert Into @RtnValue (data)
Select Data = ltrim(rtrim(@RowData))
Return
END
用法如下:
SELECT s FROM dbo.Split(' ', @description)
它工作得非常好,但现在我收到了错误:
声明终止。最大值 递归100已经筋疲力尽 在声明完成之前。
有没有人就什么是实现这个目标的好方法提出建议?
答案 0 :(得分:2)
没关系。为了防止其他人遇到同样的问题,here中的以下内容适用于大字符串:
CREATE FUNCTION dbo.SplitLarge(@String varchar(8000), @Delimiter char(1))
returns @temptable TABLE (items varchar(8000))
as
begin
declare @idx int
declare @slice varchar(8000)
select @idx = 1
if len(@String)<1 or @String is null return
while @idx!= 0
begin
set @idx = charindex(@Delimiter,@String)
if @idx!=0
set @slice = left(@String,@idx - 1)
else
set @slice = @String
if(len(@slice)>0)
insert into @temptable(Items) values(@slice)
set @String = right(@String,len(@String) - @idx)
if len(@String) = 0 break
end
return
end
答案 1 :(得分:2)
此函数taken from here使用.Nodes并避免循环和递归CTES
CREATE FUNCTION dbo.Split(@data NVARCHAR(MAX), @delimiter NVARCHAR(5))
RETURNS @t TABLE (data NVARCHAR(max))
AS
BEGIN
DECLARE @textXML XML;
SELECT @textXML = CAST('<d>' + REPLACE(@data, @delimiter, '</d><d>') + '</d>' AS XML);
INSERT INTO @t(data)
SELECT T.split.value('.', 'nvarchar(max)') AS data
FROM @textXML.nodes('/d') T(split)
RETURN
END
GO
答案 2 :(得分:0)
我遇到以下代码适合我的情况。该代码使用了replace函数和SQL 2008使用单个insert语句插入多行的能力。这种方法唯一的缺点,如果真的是一个缺点,它只限于1000次分裂。
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[StringSegmenter]') AND type in (N'U'))
DROP TABLE [dbo].[StringSegmenter]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[StringSegmenter]') AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[StringSegmenter](
[ss_id] [int] IDENTITY(1,1) NOT NULL,
[ss_segment] [varchar](max) NOT NULL,
CONSTRAINT [PK_StringSegmenter] PRIMARY KEY CLUSTERED
(
[ss_id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
END
GO
SET ANSI_PADDING OFF
GO
truncate table scratchpad.dbo.stringsegmenter
declare @String varchar(max)
declare @Splitter varchar(10)
set @String = '1,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,2222222222222222222,3,4,55555555555555555555555,2222222222222222222,3,4,55555555555555555555555,666666666666666666666666666666,2222222222222222222,3,4,55555555555555555555555,666666666666666666666666666666,2222222222222222222,3,4,55555555555555555555555,666666666666666666666666666666,2222222222222222222,3,4,55555555555555555555555,666666666666666666666666666666'
set @Splitter = ','
set @String = 'Insert [dbo].[StringSegmenter] Values (''' + replace(@string, @splitter,'''),(''') + ''')'
select @String
execute (@String)
Select * from [dbo].[StringSegmenter] order by ss_id