SQL Server 2008中的树结构

Question

在SQL Server 2008中;

我有一棵树。我需要得到节点n的所有子节点（见图）和这些子节点的所有子节点等，直到叶子节点相当简单。我还需要能够说'取节点o，上到树直到我们到达m并且因为m是节点n的子节点，将节点o的某些属性设置为节点m的某些属性。节点o可以是3级深（如图所示）或45级深，x级深。

这将获取给定节点（或区域）的所有子项

    --Return all sub-area structure of an area:

      WITH temp_areas (ParentAreaID, AreaID, [Name], [Level]) AS
      (
            SELECT ParentAreaID, AreaID, [Name], 0
            FROM lib_areas WHERE AreaID = @AreaID
            UNION ALL
            SELECT B.ParentAreaID, B.AreaID, B.[Name], A.Level + 1
            FROM temp_areas AS A, lib_areas AS B
            WHERE A.AreaID = B.ParentAreaID
      )

INSERT INTO @files (id) SELECT fileid FROM lib_filesareasxref where areaid in (select  areaid from temp_areas)

while exists (select * from @files)
begin
select top 1
@ID = id
from
@files ORDER BY id DESC

delete from @files where id = @id

Answer 1

这将从@node_o追溯到@node_m或者到达树顶（如果@node_m不高于@node_o）

  WITH
    parents
  AS
  (
    SELECT
      A.ParentAreaID, A.AreaID, A.[Name], 0
    FROM
      lib_areas  AS A
    WHERE
      A.AreaID = @node_o

    UNION ALL

    SELECT
      A.ParentAreaID, A.AreaID, A.[Name], B.Level + 1
    FROM
      lib_areas  AS A
    INNER JOIN
      parents    AS B
        ON A.AreaID = B.ParentAreaID
    WHERE
      B.AreaID <> @node_m
  )
  SELECT
    *
  FROM
    parents

Answer 2

我建议在您的表格中使用HierarchyID数据类型，并使用GetAncestor方法