6

有没有办法将字符串（从特定列）拆分为 n 个字符而不会破坏单词，每个结果都在自己的行中？

例子：

2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the PSO department  Customer states terms should be Net 60 not Net 30.  Please review signed contract for this information.

结果：

2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the
PSO department  Customer states terms should be Net 60 not Net 30.
Please review signed contract for this information.

我知道我可以charindex用来查找最后一个空格，但我不确定如何获取剩余的空格并将它们作为行返回。

4

4 回答 4

4

尝试这样的事情。可能是您可以创建以下实现的 SQL 函数。

DECLARE @Str VARCHAR(1000)
SET @Str = '2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the PSO department  Customer states terms should be Net 60 not Net 30.  Please review signed contract for this information.'

DECLARE @End INT
DECLARE @Split INT

SET @Split = 100

declare @SomeTable table
(
  Content varchar(3000)
)


WHILE (LEN(@Str) > 0)
BEGIN
    IF (LEN(@Str) > @Split)
    BEGIN
        SET @End = LEN(LEFT(@Str, @Split)) - CHARINDEX(' ', REVERSE(LEFT(@Str, @Split)))
        INSERT INTO @SomeTable VALUES (RTRIM(LTRIM(LEFT(LEFT(@Str, @Split), @End))))
        SET @Str = SUBSTRING(@Str, @End + 1, LEN(@Str))
    END
    ELSE
    BEGIN
        INSERT INTO @SomeTable VALUES (RTRIM(LTRIM(@Str)))
        SET @Str = ''
    END
END

SELECT *
FROM @SomeTable

输出将是这样的：

2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the
PSO department  Customer states terms should be Net 60 not Net 30.  Please review signed contract
for this information.
于 2012-06-01T15:20:54.180 回答
2

只是为了看看它是否可以完成，我想出了一个不循环的解决方案。它是基于别人的函数来根据分隔符拆分字符串。

注意： 这要求您提前知道最大令牌长度。该函数将在遇到比指定行长更长的标记时停止返回行。可能还潜伏着其他错误，因此请谨慎使用此代码。

CREATE FUNCTION SplitLines
(
    @pString    VARCHAR(7999),
    @pLineLen   INT,
    @pDelim     CHAR(1)
)
RETURNS TABLE
   WITH SCHEMABINDING
AS  
RETURN
WITH
      E1(N) AS ( --=== Create Ten 1's
                 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 --10
               ),
      E2(N) AS (SELECT 1 FROM E1 a, E1 b),   --100
      E4(N) AS (SELECT 1 FROM E2 a, E2 b),   --10,000
cteTally(N) AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT N)) FROM E4),
lines AS (
  SELECT TOP 1
         1 as LineNumber,
         ltrim(rtrim(SUBSTRING(@pString, 1, N))) as Line,
         N + 1 as start
  FROM cteTally
  WHERE N <= DATALENGTH(@pString) + 1
    AND N <= @pLineLen + 1
    AND SUBSTRING(@pString + @pDelim, N, 1) = @pDelim
  ORDER BY N DESC
UNION ALL
  SELECT LineNumber, Line, start
  FROM (
    SELECT LineNumber + 1 as LineNumber,
           ltrim(rtrim(SUBSTRING(@pString, start, N))) as Line,
           start + N + 1 as start,
           ROW_NUMBER() OVER (ORDER BY N DESC) as r
    FROM cteTally, lines
    WHERE N <= DATALENGTH(@pString) + 1 - start
      AND N <= @pLineLen
      AND SUBSTRING(@pString + @pDelim, start + N, 1) = @pDelim
  ) A
  WHERE r = 1
)
SELECT LineNumber, Line
FROM lines

它实际上非常快，你可以做一些很酷的事情，比如加入它。这是一个简单的示例，它从表中的每一行中获取第一行：

declare @table table (
  id int,
  paragraph varchar(7999)
)
insert into @table values (1, '2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the PSO department  Customer states terms should be Net 60 not Net 30.  Please review signed contract for this information.')
insert into @table values (2, 'Is there a way to split a string (from a specific column) to n-number chars without breaking words, with each result in its own row?')

select t.id, l.LineNumber, l.Line, len(Line)
from @table t
cross apply SplitLines(t.paragraph, 42, ' ') l
where l.LineNumber = 1
于 2012-06-01T20:27:04.323 回答
2

我读了一些文章，每篇文章都有错误或性能不佳，或者无法在我们想要的小块或大块中工作。您甚至可以在本文下面的任何答案中阅读我的评论。最后我找到了一个很好的答案，并决定在这个问题中分享它。我没有在各种情况下检查性能，但我认为对于大小块长度来说是可以接受的并且工作正常。这是代码：

CREATE function SplitString
(   
    @str varchar(max),
    @length int
)
RETURNS @Results TABLE( Result varchar(50),Sequence INT ) 
AS
BEGIN

DECLARE @Sequence INT 
SET @Sequence = 1

    DECLARE @s varchar(50)
    WHILE len(@str) > 0
    BEGIN
        SET @s = left(@str, @length)
        INSERT @Results VALUES (@s,@Sequence)

        IF(len(@str)<@length)
        BREAK

        SET @str = right(@str, len(@str) - @length)
        SET @Sequence = @Sequence + 1
    END
    RETURN 
END

来源是@Rhyno 对这个问题的回答：TSQL UDF To Split String Every 8 Characters

希望这有帮助。

于 2014-10-20T09:08:08.610 回答
0

我知道这有点晚了，但递归 cte 可以实现这一点。

您还可以使用包含一系列数字的种子表作为起始索引的乘数输入子字符串。

于 2012-06-01T18:51:20.947 回答