Question

我有一个像'aabbcczx'这样的字符串，我需要将该字符串除以2个字符。预期的结果是这样的：

aabbcczx aa aabbcczx bb aabbcczx cc aabbcczx zx

我该怎么做？还应考虑字符串的长度逐行更改。

谢谢

Answer 1

如果总是2个字符：

SELECT  A.Val,
        CA1.N,
        SUBSTRING(A.Val,n,2)
FROM    (
            VALUES ('aabbcczx')
        ) AS A(Val)
CROSS
APPLY   dbo.GetNums(1,LEN(A.Val)) AS CA1
WHERE   CA1.n % 2 = 1;

GetNums是一个数字表/演算表生成器，您可以在线找到一些资源。

它将提供每个字符的位置，我们可以在substring起始位置使用它。 where子句使用MOD来表示，因此我们仅显示所有其他起始位置

Answer 2

您可以使用递归查询：

with cte as (
      select convert(varchar(max), left(str, 2)) as val2, convert(varchar(max), stuff(str, 1, 2, '')) as rest, str
      from (values ( 'aabbcczx' )) v(str)
      union all
      select left(rest, 2) as val2, stuff(rest, 1, 2, '') as rest, str
      from cte
      where rest <> ''
     )
select str, val2
from cte;

Answer 3

您可以使用递归查询来提取字符对：

with instring as 
 ( select 'aabbcczx' as s )
 , splitter as
 (
   select s, substring(s, 1, 2) as rslt, 3 as next -- first two chars
   from instring
   union all
   select s, substring(s, next, 2), next + 2       -- next two chars
   from splitter
   where len(s) >= next
 )
select *
from splitter

请参见dbfiddle

sql字符串拆分为定义的字符数

3 个答案: