PostGIS 爆管分析之找出上游阀门

环境：

Win10

ArcMap10.4（用于数据处理）

postgresql9.4

postgis2.2.3

pgRouting2.3（postgresql插件）

说明：

继上一篇文章做了爆管分析找出周围所有影响阀门后（参见：https://www.cnblogs.com/giser-s/p/11662932.html），发现在业务上使用有局限性，因为通常爆管以后我并不需要关闭所有周围阀门，而是只要关闭上游阀门即可。

下面的方法，是在查找到周围所有阀门的基础上继续的，在周围阀门中找出与他相接的上游阀门

步骤：

 1、在PostGIS中，建立方向模型，模拟气体流向。原理就是新增length或者reverse_cost（关键字），与source/target方向一致的，则length为值，reverse_cost为设一个大点的值9999999；如source/target方向不一致，则给reverse_cost赋值，length为设一个大点的值9999999。

这里在查询时，pgr_dijkstraCost会识别关键词cost和reverse_cost

双向查询时不用关注reverse_cost（注意cost字段一定要有，或可以如下例子将length命名cost的别名）

SELECT * FROM pgr_dijkstra( 'SELECT gid AS id, source, target, length as cost  FROM zy', 15139, 13670, directed := false);

单向查询时需要加上reverse_cost一起查（注意cost字段一定要有，或可以如下例子将length命名cost的别名）

SELECT * FROM pgr_dijkstra( 'SELECT gid AS id, source, target, length as cost,reverse_cost as reverse_cost  FROM zy', 15139, 13670, directed := true);

#正向结果：

#逆向结果：

2、这里查询到爆点周围所有影响阀门后，需要进行记录，这里采用拼接成字符串记录在数组中（这里略复杂，不同于上一博文直接返回输出了）

格式：[{v_uptap_gid||','||cast(v_uptap_geom as text)||','||up_temprow.source]}]

说明：[{阀门gid，转成字符串的geom，管段的头source}]

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;
          IF (res_tap_pipe is not null) THEN
            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;

3、v_cost是周围所有阀门，利用pgRouting的pgr_dijkstraCost函数，逆向找出与爆点管段相接的阀门。

    --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---'||cast(m_cost 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
        FOREACH m_tap_pipe IN ARRAY res_tap_pipe
        LOOP
          raise notice '%' , 'm_cost---'||cast(m_cost as text)  ;
          raise notice '%' , 'm_tap_pipe---'||cast(m_tap_pipe 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;
        END LOOP;
      END IF;
    END LOOP;

4、附上全部存储过程

 -- Function: test_getpoint8(character varying, double precision, double precision)

-- DROP FUNCTION test_getpoint8(character varying, double precision, double precision);

CREATE OR REPLACE FUNCTION test_getpoint8(
    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;
    raise notice '%' , 'v_startSource---'||cast(v_startSource as text);
    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;
          IF (res_tap_pipe is not null) THEN
            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;
      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---'||cast(m_cost 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 = 0) THEN
        FOREACH m_tap_pipe IN ARRAY res_tap_pipe
        LOOP
          raise notice '%' , 'm_cost---'||cast(m_cost as text)  ;
          raise notice '%' , 'm_tap_pipe---'||cast(m_tap_pipe 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;
        END LOOP;
      END IF;
    END LOOP;

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

$BODY$
  LANGUAGE plpgsql VOLATILE STRICT
  COST 100
  ROWS 1000;
ALTER FUNCTION test_getpoint8(character varying, double precision, double precision)
  OWNER TO postgres;

结尾：

此文算是半成品文章，代码很乱也没有进行优化，很多没有用到的变量没有删掉，这里暂且当作思路的记录。

算法上还有很多需要改进，这里只是在找到所有周边阀门的基础上继续往下写的，其实可以不用分两块，直接上来就开始找上游阀门（算法留待后面继续优化）

-- Function: test_getpoint8(character varying, double precision, double precision)
-- DROP FUNCTION test_getpoint8(character varying, double precision, double precision);
CREATE OR REPLACE FUNCTION test_getpoint8(    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;     raise notice '%' , 'v_startSource---'||cast(v_startSource as text);    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;          IF (res_tap_pipe is not null) THEN            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;      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---'||cast(m_cost 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 = 0) THEN                  FOREACH m_tap_pipe IN ARRAY res_tap_pipe         LOOP          raise notice '%' , 'm_cost---'||cast(m_cost as text)  ;          raise notice '%' , 'm_tap_pipe---'||cast(m_tap_pipe 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;        END LOOP;      END IF;    END LOOP;
     raise notice '%' , '上游阀门---'||cast(v_up_cost as text);     END IF;end;  
$BODY$  LANGUAGE plpgsql VOLATILE STRICT  COST 100  ROWS 1000;ALTER FUNCTION test_getpoint8(character varying, double precision, double precision)  OWNER TO postgres;