遞歸查詢樹tree 根據子節點查詢父級

根據父節點查詢子集 https://blog.csdn.net/wjy550823795/article/details/100703615

表結構就是正常的id 與 父類id 如上鍊接所示

SELECT T1.LEVEL1,T2.*
FROM ( 
    SELECT 
        @r AS _id, 
        (SELECT @r := parent_id FROM project_grouping WHERE gid = _id) AS parent_id, 
        @l := @l + 1 AS LEVEL1 
    FROM 
        (SELECT @r := 8, @l := 0) vars, 
        project_grouping h 
    WHERE @r <> 0) T1 
JOIN project_grouping T2 
ON T1._id = T2.gid 
ORDER BY T1.LEVEL1 DESC 

@r：= #{8} 爲你要查詢的子節點id

粘貼親測可用

返回結果