流段的上游查询

stone52025-12-05 9:34

mysql 8.0环境

使用"点位"表（positions)，主键id，点位类型position_type_id（监测点、汇接点），经纬度，表中已有监测点记录，补充汇接点数据；

创建"流段"表(b_flow_segment)，主键id，入口点in_pos_id，出口点out_pos_id，途经路径，，录输入所有监测点和汇接点之间的流段；

递归查询：点位30的所有上游管段：

sql 复制代码

with recursive t as (SELECT * FROM `b_flow_segment` WHERE out_pos_id=30 union all select a.* from b_flow_segment a join t on a.out_pos_id = t.in_pos_id) select id,in_pos_id,out_pos_id from t

递归查询：点位30的所有上游监测点：

sql 复制代码

with recursive t as (SELECT * FROM `b_flow_segment` WHERE out_pos_id=30 union all select a.* from b_flow_segment a join t on a.out_pos_id = t.in_pos_id) select t.id,t.in_pos_id,positions.title from t left join positions on t.in_pos_id=positions.id where positions.position_type_id=46

查询点位30到点位5之间的管段：

。。。

查询5点位到24点位间的路径：

sql 复制代码

WITH RECURSIVE shortest_path(in_pos, out_pos, depth, path) AS (
    SELECT 
        in_pos, 
        out_pos, 
        1, 
        concat(CAST(in_pos AS CHAR) ,',' , CAST(out_pos AS CHAR)) 
    FROM b_flow_segment
    WHERE in_pos = 5

    UNION ALL

    SELECT 
        a.in_pos, 
        a.out_pos, 
        shortest_path.depth + 1, 
        CONCAT(shortest_path.path, ',', CAST(a.out_pos AS CHAR))
    FROM shortest_path
    JOIN b_flow_segment a ON shortest_path.out_pos = a.in_pos
    WHERE shortest_path.depth <= 9
)
SELECT * FROM shortest_path 
where out_pos=24
ORDER BY depth