MS SQL Server：高级子字符串，将一个字符串列拆分为多列

Question

我在表格中有一个列，我想将内容分成不同的列，破折号的位置并不总是相同的。请提供更简单的代码。

谢谢。

       COL1
AGH-WH6X-23-4534-OPDQE-QADF  
xxx-xxxx-xxxx-xxxx-xxx-xxxx    
xxx-xxxx-xxxxxx-xxxx-xxxxx-xx 
x-xx-xxxx-xxxxxx-xxxx-xxx-xx    
xxx-xx-xxxx-xxxx-xxx-xxx-x 
xxx-xxxx-xxxxxx-xxxxxx-xxx-xx    
x-xxx-xxxx-xxxx-xxxxxx-xxx-xx 
xxx-xxxxx-xxxx-xxxxxx-xxx-xx

期望：

COL2  COL3  COL4  COL5  COL6   COL7
AGH   WH6X  23    4534  OPDQE  QADF
xxx   xxxx  xxxx  xxxx  xxx    NULL

Answer 1

一种方法是带有聚合的递归 CTE：

with cte as (
      select col1, left(col1, charindex('-', col1 + '-') - 1) as val,
             1 as level,
             substring(col1, charindex('-', col1) + 1, len(col1)) as rest
      from t
      union all
      select col1, left(rest, charindex('-', rest + '-') - 1),
             level + 1,
             substring(rest, charindex('-', rest + '-') + 1, len(col1))
      from cte
      where rest > ''
     )
select max(case when level = 1 then val end) as val1,
       max(case when level = 2 then val end) as val2,
       max(case when level = 3 then val end) as val3,
       max(case when level = 4 then val end) as val4,
       max(case when level = 5 then val end) as val5,
       max(case when level = 6 then val end) as val6,
       max(case when level = 7 then val end) as val7
from cte
group by col1;