postgres SQL查询在节点JS中抛出错误

Question

我设置了一个API，在客户端用户可以计算到点之间的路由。 但是，我遇到了psql查询的麻烦，它在postgres中工作，但是当我在节点JS中使用相同的查询时，我收到了一个错误。

我正在使用nodeJS，Express和Postgres。 如果我在pgAdmin4中运行下面的查询，我会得到预期的输出。

SELECT b.gid, b.the_geom, b.cost_s, b.length_m FROM pgr_dijkstra('SELECT gid::bigint as id, source::bigint, 
                                           target::bigint, cost_s::double precision as cost, 
                                           reverse_cost_s::double precision as reverse_cost FROM ways 
                                           WHERE the_geom && ST_Expand((SELECT ST_Collect(the_geom) 
                                           FROM ways_vertices_pgr WHERE id IN(589143, 581050)), 0.01)', 
589143, 581050) a LEFT JOIN ways b ON (a.edge = b.gid);

但是当我在Node Js中使用相同的查询（见下文）时，我收到一条错误消息，指出error: syntax error at or near "&&" 。 我究竟做错了什么？

const start = parseInt(request.params.start)
const end = parseInt(request.params.end)

const sql2 = 
     "SELECT b.gid, b.the_geom, b.cost_s, b.length_m FROM pgr_dijkstra('SELECT gid::bigint as id, source::bigint,"+
     "target::bigint, cost_s::double precision as cost," +
     "reverse_cost_s::double precision as reverse_cost FROM ways" + 
     "WHERE the_geom && ST_Expand((SELECT ST_Collect(the_geom)" + 
     "FROM ways_vertices_pgr WHERE id IN(" + start + "," + end + ")), 0.01)'," +
      start + "," + end + ") a LEFT JOIN ways b ON (a.edge = b.gid);"

Answer 1

得到了答案。 我使用语法$1 ...而不是start和end ，并添加了参数的数据类型。 在我的情况下， ineteger

SELECT b.gid, b.the_geom, b.cost_s, b.length_m FROM pgr_dijkstra('SELECT gid::bigint as id, source::bigint, 
                                           target::bigint, cost_s::double precision as cost, 
                                           reverse_cost_s::double precision as reverse_cost FROM ways 
                                           WHERE the_geom && ST_Expand((SELECT ST_Collect(the_geom) 
                                           FROM ways_vertices_pgr WHERE id IN(' || $1::integer || ',' || $2::integer ||')), 0.01)', 
    $1::integer, $2::integer) a LEFT JOIN ways b ON (a.edge = b.gid);