Question

我需要为我的表tbl1

进行sql查询

像这样的表的样本内容

                        serial   ida    idb        
                          1        1       2             
                          2        1       3              
                          3        3       7             
                          4        3       6              
                          5        2       4               
                          6        2       6

。

在表tbl1列中ida和idb相关，如1与2和3相关，2与4和6相关

ida值1 s相关数据是2和3，我想选择1的相关数据（2和3）的相关数据。

2和3 s相关数据是7,6和4,6。因此输出将是（7,6,4）
。我需要一个SQL查询来显示此输出。任何人都可以分享一些如何做到这一点......

Answer 1

SELECT DISTINCT idb FROM tbl1 WHERE ida = 2 OR ida = 3;

这是你在找什么？

Answer 2

编辑：已更正确定层次结构的子分支。

这可能有一些用处：

-- Sample data.
declare @Table as table ( serial int identity, ida int, idb int )
insert into @Table ( ida, idb ) values
  ( 1, 2 ), ( 1, 3 ),
  ( 3, 7 ), ( 3, 6 ),
  ( 2, 4 ), ( 2, 6 )

select * from @Table

-- Demonstrate recursive query.
; with CTE as (
  -- Start with ida = 1.
  select serial, ida, idb, 1 as depth, path = cast( right( '000000' + cast( ida as varchar(6) ), 6 ) as varchar(1024) )
    from @Table
    where ida = 1
  union all
  -- Add each row related to the most recent selected row(s).
  select T.serial, T.ida, T.idb, C.depth + 1, cast( C.path + right( '000000' + cast( T.ida as varchar(6) ), 6 ) as varchar(1024) )
    from CTE as C inner join
      @Table as T on T.ida = C.idb
  )
-- Show everything.
select *
  from CTE

-- Repeat the recursive query.
; with CTE as (
  -- Start with ida = 1.
  select serial, ida, idb, 1 as depth, path = cast( right( '000000' + cast( ida as varchar(6) ), 6 ) as varchar(1024) )
    from @Table
    where ida = 1
  union all
  -- Add each row related to the most recent selected row(s).
  select T.serial, T.ida, T.idb, C.depth + 1, cast( C.path + right( '000000' + cast( T.ida as varchar(6) ), 6 ) as varchar(1024) )
    from CTE as C inner join
      @Table as T on T.ida = C.idb
  )
-- Select only the deepest children.
select distinct idb
  from CTE as C
  where not exists ( select 42 from CTE where left( path, len( C.path ) ) = C.path and len( path ) > len( C.path ))
  order by idb

左边的练习正在转动结果。

Answer 3

select distinct idb from tbl1 where ida in (select idb from tbl1 where ida = 1)

创建用于选择多个数据的SQL查询

3 个答案: