Get a dataset

Description: retrieve a dataset
uri: /datasets/trajectory/<name>
http method: GET

Sequence Diagram

Code

#retrieve a dataset/trajectory/~in given range
@app.route('/datasets/trajectory/<name>', methods=['GET'])
def retrieve_a_dataset(name):
    #conn_string = "host='192.168.100.200' dbname='hdwu' user='hdwu' password='4321'"
    #conn = pg.connect(conn_string)
    #if name == "taxi"
    args = request.args
    trajectory = []
    if 'tid' in args:
        query = "select * from trajectory." + name + " where tid=" + args['tid']+ ";"
        rows = conn.query(query).getresult()
        for row in rows:
            if len(trajectory) == 0:
                trajectory.append({'tid': row[0], 'points': [{'index': row[1], 'lon': row[2], 'lat': row[3], 'timestamp': row[4]}]})
            else: trajectory[0]['points'].append({'index': row[1], 'lon': row[2], 'lat': row[3], 'timestamp': row[4]})

    elif 'lon_s'and 'lon_e' and 'lat_s' and 'lat_e' in args:
        query = "select * from trajectory." + name + " where lon>=" + args['lon_s'] + " and lon<=" + args['lon_e'] + " and lat>=" + args['lat_s'] + " and lat<=" + args['lat_e'] + ";"
        rows = conn.query(query).getresult()
        for row in rows:
            print row
            if row[0] == len(trajectory)-1:                
                trajectory[row[0]]['points'].append({'index': row[1], 'lon': row[2], 'lat': row[3], 'timestamp': row[4]})
            else: trajectory.append({'tid': row[0], 'points': [{'index': row[1], 'lon': row[2], 'lat': row[3], 'timestamp': row[4]}]})

    else:
        query = "select * from trajectory." + name + ";"
        rows = conn.query(query).getresult()
        for row in rows:
            if row[0] == len(trajectory)-1:                
                trajectory[row[0]]['points'].append({'index': row[1], 'lon': row[2], 'lat': row[3], 'timestamp': row[4]})
            else: trajectory.append({'tid': row[0], 'points': [{'index': row[1], 'lon': row[2], 'lat': row[3], 'timestamp': row[4]}]})
    return jsonify({'trajectory': trajectory})