使用 TSQL，获取从第 60 个字符开始的字符串的正确部分，但不分解单词

Question

我正在尝试将长字符串（> 60 个字符）分成两部分，但要保持第 60 个字符的单词的完整性。

例如对于字符串one two three four five six seven eight nine ten eleven twelve thirteen fourteen，单词twelve中的字母l是第60个字符，所以我想将字符串打散为

one two three four five six seven eight nine ten eleven

和

twelve thirteen fourteen

到目前为止，只关注获取字符串的正确部分，我可以使用 REVERSE() 获取整个最后一个词

DECLARE @Input varchar(100)
SET @Input = 'one two three four five six seven eight nine ten eleven twelve thirteen fourteen'

SELECT LTRIM(RTRIM(RIGHT(@Input, CHARINDEX(' ', REVERSE(@Input)) - 1))) AS LastWholeWord
    ,  @Input           AS UnalteredString
    ,  LEN(@Input)      AS LengthOfString
    ,  LEFT(@Input, 60) AS First60

现在，我的想法是，我可以通过放入 LEFT(@Input, 60) 将最后 REVERSE() 限制为前 60 个字符，因此 LTRIM(RTRIM(RIGHT(@Input, CHARINDEX(' ', REVERSE(LEFT(@Input, 60))) - 1)))

但这似乎没有达到预期的效果。如果有人能指出正确的方向，我会很高兴！！

感谢您的宝贵时间！

Answer 1

这应该有效：

DECLARE @divingSpaceChar INT =
LEN(SUBSTRING(@Input,0, 60)) - CHARINDEX(' ', REVERSE(SUBSTRING(@Input,0, 60))) + 1

SELECT SUBSTRING(@Input, 0, @divingSpaceChar) AS leftString
SELECT LTRIM(SUBSTRING(@Input,  @divingSpaceChar, LEN(@input))) AS rightString

获取子字符串前 60 个字符中最后 space 个字符的索引。从最后一个字符索引中获取子字符串...

没有额外的变量，你可以这样做：

SELECT
RTRIM(LTRIM(SUBSTRING(@Input, LEN(SUBSTRING(@Input,0, 60)) 
- CHARINDEX(' ', REVERSE(SUBSTRING(@Input,0, 60)))+ 1, LEN(@input)))) AS RightPart,
RTRIM(LTRIM(SUBSTRING(@Input, 0, LEN(SUBSTRING(@Input,0, 60))
- CHARINDEX(' ', REVERSE(SUBSTRING(@Input,0, 60)))+ 1))) AS LeftPart

Answer 2

用正则表达式怎么样，看起来干净多了..

（我将使用 Presto 展示语法，但我认为与其他 SQL 非常相似）

正则表达式：'(.{1,60})(?= )(.*)'.
查询中注意：$1,$2 显示字符串的每个部分..

SELECT regexp_replace('one two three four five six seven eight nine ten eleven twelve thirteen fourteen',
                  '(.{1,60})(?= )(.*)', '') part1,
       regexp_replace('one two three four five six seven eight nine ten eleven twelve thirteen fourteen',
                  '(.{1,60})(?= )(.*)', '') part2


-----
Results
part1                                                    part2
one two three four five six seven eight nine ten eleven  twelve thirteen fourteen

使用 TSQL，获取从第 60 个字符开始的字符串的正确部分，但不分解单词

With TSQL, Get right part of a string starting 60th character, but not breaking up the word

sql

tsql

sql-server-2008-r2

substring