sql - 从 SQL 中的表中顺序读取值

Question

我有以下表结构，它是根据从 UI 中的选择生成的，并按照从 UI 生成的方式存储。这基本上是存储查询序列。

例如

(( Condition AND Condition) OR ( Condition ))

Id  ConditionType Value         Brackets 1     NULL        NULL           ( 2     NULL        NULL           ( 3     NULL        Condition      NULL 4     AND         NULL           NULL 5     NULL        Condition      NULL  6     NULL        NULL           ) 7     OR          NULL           NULL 8     NULL        NULL           ( 9     NULL        Condition      NULL10     NULL        NULL           )11     NULL        NULL           )

根据以上信息，我需要生成一个索引:

Id  StartIndex   EndIndex1     1           112     2            63     8           10 

关于如何做到这一点有什么想法吗？

Answer 1

编辑:在第 1 版中，我没有考虑嵌套级别。这个我测试过:)

我在 DB2 上工作，所以如果它不支持 LATERAL 连接，您可能必须为 sql-server 重构它，但是这个使用您在 DB2 上的值集产生了正确的结果:

with CTE_ONLY_BRACKETS as (
  select * 
  from   MYLIST 
  where  Brackets in('(',')')
) ,

CTE_NEST_INCREMENT as (
  select   Id
          ,Brackets
          ,case when Brackets = '(' then 1 else -1 end as NEST_INCREMENT
  from     CTE_ONLY_BRACKETS 
) ,

CTE_NEST_LEVEL as (
  select    Id
           ,Brackets
           ,S.NEST_LEVEL 
  from      CTE_NEST_INCREMENT C
  cross join lateral (
    select  sum( NEST_INCREMENT ) as NEST_LEVEL
    from    CTE_NEST_INCREMENT S
    where   S.Id <= C.Id
  ) as S

)

select   row_number() over() as Id
        ,L.Id as StartIndex
        ,R.Id as EndIndex
from     CTE_NEST_LEVEL R

cross join lateral (
  select L.Id
  from   CTE_NEST_LEVEL L
  where  L.Brackets = '('
    and  L.Id < R.Id
    and  L.NEST_LEVEL = R.NEST_LEVEL + 1
  order by L.Id desc
  fetch  first row only
) as L

where    R.Brackets = ')'

order by L.Id