Question

我是node.js的新手。我想要实现的目标如下：

连接到我的postgresql数据库，获取三个地方的信息（id，coordinates）。对于我需要的每个地方：
使用上一步中获得的坐标调用天气api并获取该地点的信息。
将返回的json插入数据库中。我得到8个小时的物体，每3小时有一次天气信息（0,3,6,9,12,15,18,21）。我需要遍历这些对象，然后将它们存储在数据库中的8条记录中。

到目前为止，我编写了以下代码：

function insert_forecast_spot(id, body, client) {
  var date = body.data.weather[0].date;
  var callbacks = 0;

    for (var i=0; i < 8; i++) {

    var hourly = body.data.weather[0].hourly[i];

    client.query('INSERT into parte (id, date, time) VALUES($1, $2, $3)',
                      [id, date, hourly.time], 
                      function(err, result) {
                             if (err) {
                                console.log(err); 
                              } else {
                                console.log('row inserted: ' + id + ' iteration ' + i);
                                callbacks++;
                                if (callbacks === 8) {
                                  console.log('All callbacks done!from id '+id);
                                }
                              }   
                            });
    } //for
  } // function


app.get('/getapi', function(req, res, next){  
//------------ BBDD CONNECTION----------------

  pg.connect(conString, function(err, client, done) {
    if(err) {
      // example how can you handle errors
      console.error('could not connect to postgres',err);
      return next(new Error('Database error'));
    }
    client.query('SELECT * from places where id>3274 and id<3278', function(err, result) {
      if(err) {
        console.error('error running query',err);
        done();
        return next(new Error('Database error'));
      }
      done();
      var first_callback = 0;
      for (var y=0;  y<result.rows.length; y++) {
          console.log('y'+y);
          var coords = JSON.parse(result.rows[y].json).coordinates;
          var id = result.rows[y].id;
          var input = {
            query: coords[1] + ',' + coords[0] ,
            format: 'JSON',
            fx: ''
          };

          var url = _PremiumApiBaseURL + "marine.ashx?q=" + input.query + "&format=" + input.format + "&fx=" + input.fx + "&key=" + _PremiumApiKey;  

          request(url,function (err, resp, body){

              body = JSON.parse(body);
              if (!err && resp.statusCode == 200) {

                  insert_forecast_spot(id,body, client);
              }
              else { 
                 console.error(err);
                 done();    // done(); is rough equivalent of client.end();  
              }
            });

      first_callback++;
      if (first_callback === result.rows.length-1) {
        console.log('All global callbacks done!');
        done();    // done(); is rough equivalent of client.end();
        res.send("done");
      }} 
    }); // SELECT 
  }); // CONNECT
}); // app.get

它的作用是尝试三次插入id = 3277点的预测！

控制台日志如下：

y0
y1
All global callbacks done!
GET /getapi 200 40ms - 4b
y2
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
row inserted: 3277 iteration 8
All callbacks done!from id 3277
{ [error: duplicate key value violates unique constraint "parte_pkey"]
  name: 'error',
  length: 178,
  severity: 'ERROR',
  code: '23505',
  detail: 'Key (id, date, "time")=(3277, 2013-11-22, 0) already exists.',
  hint: undefined,
  position: undefined,
  internalPosition: undefined,
  internalQuery: undefined,
  where: undefined,
  file: 'nbtinsert.c',
  line: '397',
  routine: '_bt_check_unique' }

这个最后的错误重复16次，因为它试图再次插入该地点的8个记录两次。

Node.js函数不刷新id参数（作用域问题）？

0 个答案: