有幾種SQL拆分函數，從循環驅動到使用xml命令，甚至使用數字表。我還沒有找到支持文本限定符的文件。SQL拆分函數處理字符串與文本限定符之間出現的分隔符？
使用下面的示例字符串，我想分割「，」，但不是當它出現在雙引號或單引號之間時。
示例數據：
[email protected], "Sally \"Heat\" Jones" <[email protected]>, "Mark Jones" <[email protected]>, "Stone, Ron" <[email protected]>
應該返回一個表：
[email protected]
"Sally \"Heat\" Jones" <[email protected]>
"Mark Jones" <[email protected]>
"Stone, Ron" <[email protected]>
我知道這是一個複雜的查詢/功能，但任何建議或任何指導，將MUCHO讚賞。
這是一個快速的解決方案，它不是完美的，它沒有堆棧，所以它會將引號內的逗號視爲分隔符。
alter function fnSplit
(
@Delim char(1),
@List nvarchar(4000)
)
returns table as
return
with
Strings(PosIdx) as
(
select 1
union all
select PosIdx + 1 from Strings where PosIdx < 4000
)
select
ltrim(rtrim(substring(@List, PosIdx, charindex(@Delim, @List + @Delim, PosIdx) - PosIdx))) as value
from
Strings
where
PosIdx <= convert(int, len(@List))
and substring(@Delim + @List, PosIdx, 1) = @Delim
go
select * from fnSplit(',', '[email protected], "Sally \"Heat\" Jones" <[email protected]>, "Mark Jones" <[email protected]>, "Stone, Ron" <[email protected]>')
option (maxrecursion 0)
CREATE FUNCTION [dbo].[udfSplit]
(
@nvcString nvarchar(max),
@nvcDelimiter nvarchar(1),
@nvcTQ nvarchar(1)
)
RETURNS @tblTokens TABLE (
Token nvarchar(max)
)
AS
BEGIN
DECLARE @intCounter int
DECLARE @nvcToken nvarchar(4000)
DECLARE @nvcCurrentChar nvarchar(1)
DECLARE @intStart int
IF @nvcString <> ''
BEGIN
SET @intCounter = 1
SET @nvcToken = ''
SET @intStart = 0
--Loop through each character of the string
WHILE @intCounter <= LEN(@nvcString)
BEGIN
SET @nvcCurrentChar = SUBSTRING(@nvcString, @intCounter, 1)
--If current char is TQ
IF @nvcCurrentChar = @nvcTQ
BEGIN
--Concatonate to token
SET @nvcToken = @nvcToken + @nvcCurrentChar
--If this is the end TQ
IF @intStart <> 0
BEGIN
--Fix TQ
SET @nvcToken = dbo.udfRemoveTQFromToken(@nvcToken, @nvcTQ)
IF @nvcToken <> ''
BEGIN
INSERT INTO @tblTokens (Token) VALUES (@nvcToken)
SET @nvcToken = ''
END
--Reset TQ
SET @intStart = 0
END
ELSE
BEGIN
SET @nvcToken = dbo.udfRemoveTQFromToken(@nvcToken, @nvcTQ)
IF @nvcToken <> ''
BEGIN
INSERT INTO @tblTokens (Token) VALUES (@nvcToken)
SET @nvcToken = ''
END
--Mark TQ start position
SET @intStart = @intCounter
END
END
ELSE IF @intStart = 0 AND @nvcCurrentChar = @nvcDelimiter
BEGIN
--If not inside TQ, and char is Delimiter
SET @nvcToken = dbo.udfRemoveTQFromToken(@nvcToken, @nvcTQ)
IF @nvcToken <> ''
BEGIN
INSERT INTO @tblTokens (Token) VALUES (@nvcToken)
SET @nvcToken = ''
END
END
ELSE
BEGIN
--Current char is not TQ or Delim, add to current token
SET @nvcToken = @nvcToken + @nvcCurrentChar
END
SET @intCounter = @intCounter + 1
END
END
SET @nvcToken = dbo.udfRemoveTQFromToken(@nvcToken, @nvcTQ)
IF @nvcToken <> ''
BEGIN
--Current Token has not been added to table
INSERT INTO @tblTokens (Token) VALUES (@nvcToken)
END
RETURN
END
GO
CREATE FUNCTION [dbo].[udfRemoveTQFromToken]
(
@nvcToken nvarchar(4000),
@nvcTQ nvarchar(1)
)
RETURNS nvarchar(4000) AS
BEGIN
DECLARE @nvcReturn nvarchar(4000)
--Trim token, needs to be done first,
--as we dont want to trim any spaces within the TQ
--unless it was malformed
SET @nvcReturn = LTRIM(RTRIM(@nvcToken))
--If Left char is TQ
IF LEFT(@nvcReturn, 1) = @nvcTQ
BEGIN
--Though both cases perform the removal of the left most char (opening TQ)
--We need to perform a trim after removal ONLY if it was malformed
IF RIGHT(@nvcReturn, 1) <> @nvcTQ
BEGIN
--But no matching end TQ, malformed
--fix by removing left most char (the opening TQ)
SET @nvcReturn = RIGHT(@nvcReturn, LEN(@nvcReturn) - 1)
--Reapply the LTRIM, incase there were spaces after the opening TQ
SET @nvcReturn = LTRIM(@nvcReturn)
END
ELSE
BEGIN
--has matching end TQ, well-formed
--fix by removing left most char (the opening TQ)
SET @nvcReturn = RIGHT(@nvcReturn, LEN(@nvcReturn) - 1)
END
END
--Remove the right most char (the closing TQ)
IF RIGHT(@nvcReturn, 1) = @nvcTQ
SET @nvcReturn = LEFT(@nvcReturn, LEN(@nvcReturn) - 1)
RETURN @nvcReturn
END
這裏是我的解決方案：
CREATE FUNCTION fnSplitString
(
@input nvarchar(MAX)
)
RETURNS @emails TABLE
(
email nvarchar(MAX)
)
AS
BEGIN
DECLARE @len int = LEN(@input)
DECLARE @pos int = 1;
DECLARE @start int = 1;
DECLARE @ignore bit = 0;
WHILE(@pos<[email protected])
BEGIN
DECLARE @ch nchar(1) = SUBSTRING(@input, @pos, 1);
IF (@ch = '"' or @ch = '''')
BEGIN
SET @ignore = 1 - @ignore;
END
IF (@ch = ',' AND @ignore = 0)
BEGIN
INSERT @emails VALUES (SUBSTRING(@input, @start, @[email protected]));
SET @start = @pos+1;
END
SET @pos = @pos + 1;
END
IF (@start<>@pos)
BEGIN
INSERT @emails VALUES (SUBSTRING(@input, @start, @[email protected]));
END
RETURN
END
GO
DECLARE @input nvarchar(max) = '[email protected], "Sally \"Heat\" Jones" <[email protected]>, "Mark Jones" <[email protected]>, "Stone, Ron" <[email protected]>';
select * from fnSplitString(@input)
這顯然不是原來的問題的解決方案。 我想分割「，」，但不是當它出現在雙引號或單引號之間時。 – Ron 2010-05-20 16:48:29