SQL中的递归选择

declare @T table(  Id int primary key,  Name nvarchar(255) not null,  ParentId int)insert into @T values(1,   'TestName1',    NULL),(2,   'TestName2',    1),(3,   'TestName3',    2),(4,   'TestName4',    NULL),(5,   'TestName5',    1)declare @Id int = 1;with cte as(    select T.*  from @T as T  where T.Id = @Id  union all  select T.*  from @T as T    inner join cte as C      on T.ParentId = C.Id)select *from cte

结果

Id          Name      ParentId----------- -------------------- -----------1TestName1 NULL2TestName2 15TestName5 13TestName3 2