PostGIS 爆管分析之找出总阀门

这个算法算是被摒弃了，但是很多自己思考过后留下的成果，虽然不用了，留着做记录。

算法目的是为了发生爆管后找到总阀门，这里分了几个步骤：

1、找到爆管点所在管段

2、通过遍历找到爆管点所有影响的阀门

3、找到影响阀门中的上游阀门

4、在上游阀门中进行遍历，看相互关系，与其他阀门都联通的则视为总阀门

5、找出阀门中的总阀门

#考虑了一下，所有与爆点相连的上游阀门其实在爆管发生后都需要关闭。所以算法中4、5步，不需要了。

-- Function: test_getpoint7(character varying, double precision, double precision)
-- DROP FUNCTION test_getpoint7(character varying, double precision, double precision);
CREATE OR REPLACE FUNCTION test_getpoint7(
    IN tbl character varying,
    IN startx double precision,
    IN starty double precision)
  RETURNS TABLE(v_gid integer, v_res geometry, v_type integer) AS
$BODY$  

declare  
    v_startLine geometry;--离起点最近的线 
    v_startTarget integer;--距离起点最近线的终点 
    v_startSource integer; 
    v_statpoint geometry;--在v_startLine上距离起点最近的点  
    v_endpoint geometry;--在v_endLine上距离终点最近的点  
    v_up_source integer;--游标，记录是否有记录
    v_up_idx integer;--记录遍历到多少层级
    v_uptap_gid integer;--上游阀门gid
    v_uptap_geom geometry;--上游阀门要素
    v_all_where integer[];--记录所有查询过的管段
    v_up_where integer[];--where条件，将遍历到阀门的管段gid排除
    v_down_where integer[];--where条件，将遍历到阀门的管段gid排除
    up_temprow record ;
    --v_cost record;--记录阀门管段source（用于计算消耗，判断方向）
    m_cost integer;
    m_cost_value integer;
    temprow record;
    v_cost integer[];
    res_source integer;
    res_tap_pipe text[];
    m_tap_pipe text;
    idx_tap_pipe integer; --遍历结果游标
    m_up_cost integer;--上游阀门
    v_up_cost integer[];--上游阀门集合
    res_main_pipe integer[];--总阀门集合
    m_main_pipe integer;--总阀门
begin 
    --查询离起点最近的线 
    --3857坐标系
    --找起点15米范围内的最近线 
    execute 'select geom, source, target, ST_StartPoint(geom) as startpoint,ST_EndPoint(geom) as endpoint from ' ||tbl|| 
                            ' where ST_DWithin(geom,ST_Geometryfromtext(''point('|| startx ||' ' || starty ||')'',3857),15)
                            order by ST_Distance(geom,ST_GeometryFromText(''point('|| startx ||' '|| starty ||')'',3857))  limit 1' 
                            into v_startLine, v_startSource ,v_startTarget, v_statpoint ,v_endpoint; 
    IF(v_startLine is not null) THEN
    --查找上游阀门
    v_up_idx = 0;
    v_up_source = 1;
    --寻找上游阀门
    SELECT array_append(v_up_where, v_startSource) into v_up_where;
    --如果没有下级节点需要遍历
    WHILE array_length(v_up_where,1) > 0 
    LOOP
      --游标归零
      v_up_source = 0; 
      --记录层级
      v_up_idx = v_up_idx + 1;
      --获取当前层级节点      
      FOR up_temprow IN 
        select zy1.gid,zy1.source,zy1.target from zy zy1 where source = any(v_up_where) or target = any(v_up_where) 
        --select zy1.gid,zy1.source,zy1.target from zy zy1 where target = any(v_up_where)--找上游
      LOOP
        --清空需要查的点
        IF(v_up_source = 0) THEN
          v_up_where = null;
        END IF;
        --清空初始执行节点
        v_startSource = 0;
        --标志执行有数据
        v_up_source = 1;
        --查询管网上的点
        select t.gid,t.geom from fm t where t.gid  in (
          select a.gid from fm a,(select c.* from zy c where c.gid = up_temprow.gid) b where ST_intersects(a.geom,b.geom) 
        ) into v_uptap_gid, v_uptap_geom;  
        raise notice '%' , 'UP---'||up_temprow.gid;
        --如果没查找到阀门，则继续往下查
        IF(v_uptap_gid is null) then
          --source去重，判断如果数组中已有，则不添加
          IF (v_up_where @> ARRAY[up_temprow.source::integer] OR v_all_where @> ARRAY[up_temprow.source::integer]) THEN
          ELSE
            SELECT array_append(v_up_where,up_temprow.source) into v_up_where;
            SELECT array_append(v_all_where,up_temprow.source) into v_all_where;
          END IF;
          --target去重，判断如果数组中已有，则不添加
          IF (v_up_where @> ARRAY[up_temprow.target::integer] OR v_all_where @> ARRAY[up_temprow.target::integer]) THEN
          ELSE
            SELECT array_append(v_up_where,up_temprow.target) into v_up_where;
            SELECT array_append(v_all_where,up_temprow.target) into v_all_where;
          END IF;
        ELSE
          raise notice '%' , up_temprow.source;
          --记录阀门所在管段source
          IF (v_cost @> ARRAY[up_temprow.source::integer]) THEN
          ELSE
            SELECT array_append(v_cost,up_temprow.source) into v_cost;
            SELECT array_append(v_cost,up_temprow.target) into v_cost;
          END IF;
          --insert into v_cost values (up_temprow.gid,up_temprow.source,v_uptap_gid,v_uptap_geom );
          --insert into v_cost values (up_temprow.gid,up_temprow.target,v_uptap_gid,v_uptap_geom );
          --insert into v_cost values (up_temprow.gid,v_uptap_geom ,v_uptap_gid);
          --return next v_cost;
          --insert into v_taps values (v_uptap_gid, v_uptap_geom, up_temprow.source);
          --v_cost = up_temprow;
          --执行返回结果
          --阀门id，阀门图形要素，阀门类型（上游/下游）
          --return query
          --select v_uptap_gid as res_uptap_gid,v_uptap_geom as res_uptap_geom ,up_temprow.source as res_source;
          --raise notice '%' , 'res_tap_pipe---'||cast(res_tap_pipe as text);
          IF (res_tap_pipe is not null) THEN
            --SELECT array_append(res_tap_pipe,ARRAY[v_uptap_gid,up_temprow.source]) into res_tap_pipe;
            --select cast(res_tap_pipe as text);
            select res_tap_pipe || ARRAY[v_uptap_gid||','||cast(v_uptap_geom as text)||','||up_temprow.source] into res_tap_pipe;
          ELSE
            select ARRAY[v_uptap_gid||','||cast(v_uptap_geom as text)||','||up_temprow.source] into res_tap_pipe;
          END IF;
        END IF;
        --return next;
      END LOOP;
    END LOOP;
    --raise notice '%' , v_cost;
    raise notice '%' , 'res_tap_pipe---'||cast(res_tap_pipe as text);
    --return query select * from v_cost;
    raise notice '%' , 'v_cost---'||cast(v_cost as text);

    --查找上游阀门
    FOREACH m_cost IN ARRAY v_cost 
    LOOP
      SELECT count(*) FROM pgr_dijkstraCost('select gid as id, source, target, length as cost, reverse_cost from zy',m_cost, ARRAY[v_startSource,v_startTarget], true) where agg_cost >= 9999999 into m_cost_value;
      raise notice '%' , 'm_cost_value---'||cast(m_cost_value as text);
      --如果没有消耗大于9999999的（阈值），则认为是上游阀门
      IF(m_cost_value = 0) THEN
        --判断上游阀门间是否有上下游关系
        SELECT array_append(v_up_cost,m_cost) into v_up_cost;
      END IF;
      --IF(m_cost_value = array_length(v_cost,1)/2 - 1) THEN
        ----return query
        ----  select * from v_taps where source = m_cost;
        ----raise notice '%' , 'res_tap_pipe---'||cast(unnest(res_tap_pipe) as text);
        --FOREACH m_tap_pipe IN ARRAY res_tap_pipe 
        --LOOP
          --raise notice '%' , 'm_cost---'||cast(m_cost as text)  ;
          --IF (split_part(m_tap_pipe, ',', 3)::integer = m_cost) THEN 
            ----阀门id，阀门图形要素，阀门类型（上游/下游）
            --return query
            --select split_part(m_tap_pipe, ',', 1)::integer as res_uptap_gid,split_part(m_tap_pipe, ',', 2)::geometry  as res_uptap_geom ,split_part(m_tap_pipe, ',', 3)::integer as res_source;
          --END IF;
          --idx_tap_pipe = idx_tap_pipe+1;
        --END LOOP;
      --END IF;
    END LOOP;

    raise notice '%' , '上游阀门---'||cast(v_up_cost as text);

    --循环遍历找主阀门
    FOREACH m_up_cost IN ARRAY v_up_cost
    LOOP
        SELECT count(*) FROM pgr_dijkstraCost('select gid as id, source, target, length as cost, reverse_cost from zy',m_up_cost, v_up_cost, true) where agg_cost >= 9999999 into m_cost_value;
        IF(m_cost_value = 0) THEN          
          SELECT array_append(res_main_pipe,m_up_cost) into res_main_pipe;
        END IF;
     END LOOP;

     raise notice '%' , 'res_main_pipe---'||cast(res_main_pipe as text);
     
     IF(res_main_pipe IS NULL OR array_length(res_main_pipe,1)=0) THEN
       res_main_pipe = v_up_cost;
     END IF;

     
     FOREACH m_main_pipe IN ARRAY res_main_pipe
     LOOP
       FOREACH m_tap_pipe IN ARRAY res_tap_pipe 
       LOOP
         raise notice '%' , 'm_cost---'||cast(m_cost as text)  ;
         IF (split_part(m_tap_pipe, ',', 3)::integer = m_main_pipe) THEN 
           --阀门id，阀门图形要素，阀门类型（上游/下游）
           return query
           select split_part(m_tap_pipe, ',', 1)::integer as res_uptap_gid,split_part(m_tap_pipe, ',', 2)::geometry  as res_uptap_geom ,split_part(m_tap_pipe, ',', 3)::integer as res_source;
         END IF;
       END LOOP; 
     END LOOP;

  END IF;

--查找总阀门 --FOR temprow IN  -- select * from v_cost --LOOP -- SELECT count(*) FROM pgr_dijkstraCost('select gid as id, source, target, length as cost, reverse_cost from zy',m_cost, v_cost, true) where agg_cost <9999999 into m_cost_value; -- if(m_cost_value == ) --END LOOP;


end;  

$BODY$
  LANGUAGE plpgsql VOLATILE STRICT
  COST 100
  ROWS 1000;
ALTER FUNCTION test_getpoint7(character varying, double precision, double precision)
  OWNER TO postgres;