oracle中的sql用递归查询树格式数据

1.查询当前节点的子类

WITH cte_child (
    GRID_ID,
    GRID_NAME,
    PARENT_GRID_CODE
) AS (
    --起始条件
    SELECT
        GRID_ID,
        GRID_NAME,
        PARENT_GRID_CODE
    FROM
        T_SG_GRID
    WHERE
        GRID_ID = '2' --列出父节点查询条件
    UNION ALL
        --递归条件
        SELECT
            A .GRID_ID,
            A .GRID_NAME,
            A .PARENT_GRID_CODE
        FROM
            T_SG_GRID A
        INNER JOIN cte_child b ON (
            A .PARENT_GRID_CODE = b.GRID_ID
        )
) 
SELECT
    *
FROM
    cte_child;

2.查询当前节点的父类

WITH cte_child (
    GRID_ID,
    GRID_NAME,
    PARENT_GRID_CODE
) AS (
    --起始条件
    SELECT
        GRID_ID,
        GRID_NAME,
        PARENT_GRID_CODE
    FROM
        T_SG_GRID
    WHERE
        GRID_ID = '2' --列出父节点查询条件
    UNION ALL
        --递归条件
        SELECT
            A .GRID_ID,
            A .GRID_NAME,
            A .PARENT_GRID_CODE
        FROM
            T_SG_GRID A
        INNER JOIN cte_child b ON (
            A .GRID_ID = b.PARENT_GRID_CODE
        )
) SELECT
    *
FROM
    cte_child;

也就是把查询条件换了一个位置而已