SQL拆分或子字符串列值

我有一个sql列和值/结构，如下所示：

ColumnA
ROOT/South America/Lima/Test/Test2

运行select查询时，我想将Lima提取为列值。我无法使拆分字符串或子字符串正常工作

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有什么想法吗？

这是我获取任何分隔字符串的第n部分的方法：

DECLARE @mockupTable TABLE(ID INT IDENTITY, YourColumn VARCHAR(1000));

INSERT INTO @mockupTable VALUES('ROOT/South America/Lima/Test/Test2')
                              ,('Too/short')
                              ,('Three/parts/valid');

-劈裂是一种单衬套：

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XML的method.value允许使用XQuery获取第三个。一个优点是：如果没有第三个元素，它就不会中断，只需返回NULL。

稍微有一点，但它可以工作。基于递归cte。您可以设置分隔符、开始和结束

declare @T table (iden int identity, col1 varchar(100));
insert into @T(col1) values
       ('ROOT/South America/Lima/Test/Test2')
     , ('ROOT/South America/Peru/Test/Test2')
     , ('ROOT/South America/Venuzuala')
     , ('ROOT/South America/'); 
declare @split char(1) = '/';
declare @start int = 2;
declare @end int = 3
select @split, @start, @end;
with cte as 
(  select t.iden, t.col1, charindex(@split, t.col1) as pos    , 1 as cnt
   from @T t
   union all 
   select t.iden, t.col1, charindex(@split, t.col1, t.pos + 1), cnt + 1 
   from cte t 
   where charindex(@split, t.col1, t.pos + 1) > 0 
     and cnt+1 <= @end
)
--select * from cte order by iden, cnt;
select --t1.*, t2.*, 
       SUBSTRING(t1.col1, t1.pos+1, t2.pos-t1.pos-1) as bingo
from cte t1 
join cte t2 
  on t2.iden = t1.iden 
 and t1.cnt = @start 
 and t2.cnt = @end
order by t1.iden;

上面的代码同样具有更简单的逻辑，通过“/”结果将文本拆分为行String\u split，然后使用行编号来获得结果的顺序，如果没有按照station选择null的顺序进行排序，则每个编号都是一个级别

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因此，通过在where station中添加级别编号，将获得我们想要的级别值，上面将显示级别3

sql server 2008。在路径深度可能不固定的情况下，是否将Lima视为左侧的第三个条目，或右侧的第三个条目？确切地说，总是从左边开始的第三个条目。什么版本？2016支持字符串\拆分字符串、分隔符

      ,CAST('<x>' + REPLACE((SELECT YourColumn [*] FOR XML PATH('')),'/','</x><x>') + '</x>' AS XML).value('/x[3]','nvarchar(max)') AS ThirdPart

<x>ROOT</x>
<x>South America</x>
<x>Lima</x>
<x>Test</x>
<x>Test2</x>

declare @T table (iden int identity, col1 varchar(100));
insert into @T(col1) values
       ('ROOT/South America/Lima/Test/Test2')
     , ('ROOT/South America/Peru/Test/Test2')
     , ('ROOT/South America/Venuzuala')
     , ('ROOT/South America/'); 
declare @split char(1) = '/';
declare @start int = 2;
declare @end int = 3
select @split, @start, @end;
with cte as 
(  select t.iden, t.col1, charindex(@split, t.col1) as pos    , 1 as cnt
   from @T t
   union all 
   select t.iden, t.col1, charindex(@split, t.col1, t.pos + 1), cnt + 1 
   from cte t 
   where charindex(@split, t.col1, t.pos + 1) > 0 
     and cnt+1 <= @end
)
--select * from cte order by iden, cnt;
select --t1.*, t2.*, 
       SUBSTRING(t1.col1, t1.pos+1, t2.pos-t1.pos-1) as bingo
from cte t1 
join cte t2 
  on t2.iden = t1.iden 
 and t1.cnt = @start 
 and t2.cnt = @end
order by t1.iden;

declare @t varchar(max) = 'ROOT/South America/Lima/Test/Test2'
select * from (
select 
[value]
,ROW_NUMBER() Over (Order by (select null )) [Level]
from string_split( @t , '/')
) d
where d.Level = 3