flask+mysql+ECharts+ajax+百度地图实现数据可视化

版权声明:转载请注明出处 https://blog.csdn.net/qq_42844049/article/details/88364254

思路

1:后台连接数据库创建session对象
2:创建表关系映射
3:查询数据
4:将数据封装成特定格式(json)
5:前台通过ajax请求指定路由异步加载数据并在地图上展示
先来看一下效果
在这里插入图片描述
地图参考:https://gallery.echartsjs.com/editor.html?c=map-china-dataRange

准备:导入相应的库

连接数据库:sqlalchemy

from flask import Flask, render_template, jsonify
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import sessionmaker
from config import *

config 中保存的是数据库的url

CONN = 'mysql://root:[email protected]:3306/csv_change_mysql?charset=utf8'

注意:更换成自己的用户名、密码、数据库名称

1:连接数据库并创建session对象

Base = declarative_base()
engine = create_engine(CONN)
Session = sessionmaker(bind=engine)
session = Session()

2:创建表关系映射
我的数据库结构为:
在这里插入图片描述
表名为test,id字段没什么用主要是因为在使用使用sqlalchemy创建映时必须指定一个主键否则会报错
详情请看我的另一篇博客:

txt文件导入数据库

创建映射代码:

class Test(Base):
    __tablename__ = 'test'
    id = Column(Integer,primary_key=True,autoincrement=True)
    job = Column(String(16))
    low_salary = Column(Integer)
    high_salary = Column(Integer)
    location = Column(String(5))

3:查询数据
我需要的是地点与薪资之间的关系所以只需要这两列即可
sql:select avg(high_salary),max(high_salary),min(high_salary),count(id),location from test group by location;
查询出最高薪资、最低薪资、平均薪资、地点、以及职位数
执行sql语句

recruits = session.execute(sql)

4:封装数据:
我需要的数据格式
在这里插入图片描述
因此需要将查询结果封装成指定格式数据

def query_data():
    returnData = {}
    sql = 'select avg(high_salary),max(high_salary),min(high_salary),count(id),location from test group by location;'
    recruits = session.execute(sql)
    x = []
    for recruit in recruits:
        x.append(recruit)
    two_tuple = tuple(x)#二维数组
    print(two_tuple)
    avg_salary = []
    max_salary = []
    min_salary = []
    count_job = []
    for item in two_tuple:
        location = item[4]
        avg_salary.append({'name': location, 'value': round(item[0], 0)})
        max_salary.append({'name': location, 'value': round(item[1], 0)})
        min_salary.append({'name': location, 'value': round(item[2], 0)})
        count_job.append({'name': location, 'value': round(item[3], 0)})
    #加一个状态码让前台可以判断是否得到了数据
    if two_tuple:
        returnData['status'] = 1
    else:
        returnData['status'] = 0
    returnData['avg_salary'] = avg_salary
    returnData['max_salary'] = max_salary
    returnData['min_salary'] = min_salary
    returnData['count_job'] = count_job
    return jsonify(returnData)

到了这后台代码基本完成了

还有一点需要注意的是在数据库中查询到的数据存在中文的问题

使用json.dumps()可以使用ensure_ascii=False指定
使用jsonify可以通过设置app.config[‘JSON_AS_ASCII’] = False来显示中文

5:前台请求数据
①:导入所需的库
jquery
echarts
百度地图扩展
百度开发者中心申请的apikey
echarts地图都是基于百度地图显示的如果你没有一个百度地图的ak的话地图是无法显示的
如果你没有百度地图的ak请先申请一个步骤也很简单请参考:

百度开发者中心javascript api 文档

引入代码:

     <!--echarts-->
    <script type="text/javascript" src="http://echarts.baidu.com/gallery/vendors/echarts/echarts.min.js"></script>
    <!--jquery-->
    <script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
    <!--map-->
    <script type="text/javascript" src="http://echarts.baidu.com/gallery/vendors/echarts/map/js/china.js"></script>
    <!--ak-->
    <scripttype="text/javascript"src="https://api.map.baidu.com/apiv=2.0&ak=你申请的ak"></script>

②:ajax异步加载数据

 $(function () {
        $.ajax({
            type:'post',
            url:'/query',
            dataType:'json',
            success:function (returnData) {
                console.log(returnData);
                if (returnData.status == 1){
                //option中是地图的相关配置
                    option = {}
                }
                    var dom = document.getElementById("container");
                    var myChart = echarts.init(dom);
                    myChart.setOption(option);
                                }
                            })
                        });

在这里插入图片描述

注意请求方式为post

后台要允许post请求否则会报404

@app.route('/query',methods=['POST'])
def query_data():

还有一个细节就是地图的tooltip显示问题需要在option中配置代码为

 tooltip: {
                            trigger: 'item',
                            formatter: function(params) {
                                            var res = params.name+'<br/>';
                                            var myseries = option.series;
                                            for (var i = 0; i < myseries.length; i++) {
                                                for(var j=0;j<myseries[i].data.length;j++){
                                                    if(myseries[i].data[j].name==params.name){
                                                        res+=myseries[i].name +' : '+myseries[i].data[j].value+'</br>';
                                                    }
                                                }
                                            }
                                            return res;
                                        }
                        }

最后放上完整代码请大家酌情参考
后台:

from flask import Flask, render_template, jsonify
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import sessionmaker
from config import *
import json
Base = declarative_base()
engine = create_engine(CONN)
Session = sessionmaker(bind=engine)
session = Session()

class Test(Base):
    __tablename__ = 'test'
    id = Column(Integer,primary_key=True,autoincrement=True)
    job = Column(String(16))
    low_salary = Column(Integer)
    high_salary = Column(Integer)
    location = Column(String(5))

app = Flask(__name__)
app.config['JSON_AS_ASCII'] = False
@app.route('/query',methods=['POST'])
def query_data():
    returnData = {}
    sql = 'select avg(high_salary),max(high_salary),min(high_salary),count(id),location from test group by location;'
    recruits = session.execute(sql)
    x = []
    for recruit in recruits:
        x.append(recruit)
    two_tuple = tuple(x)#二维数组
    avg_salary = []
    max_salary = []
    min_salary = []
    count_job = []
    for item in two_tuple:
        location = item[4]
        avg_salary.append({'name': location, 'value': round(item[0], 0)})
        max_salary.append({'name': location, 'value': round(item[1], 0)})
        min_salary.append({'name': location, 'value': round(item[2], 0)})
        count_job.append({'name': location, 'value': round(item[3], 0)})
    #加一个状态码让前台可以判断是否得到了数据
    if two_tuple:
        returnData['status'] = 1
    else:
        returnData['status'] = 0
    returnData['avg_salary'] = avg_salary
    returnData['max_salary'] = max_salary
    returnData['min_salary'] = min_salary
    returnData['count_job'] = count_job
    return jsonify(returnData)
@app.route('/')
def hello_world():
    return render_template('testView.html')


if __name__ == '__main__':
    app.run()

前台页面:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>

<body>
    <div id="container" style="width: 600px; height:400px; margin: 0 auto;top: 100px"></div>
    <script type="text/javascript" src="http://echarts.baidu.com/gallery/vendors/echarts/echarts.min.js"></script>
    <script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
    <script type="text/javascript" src="http://echarts.baidu.com/gallery/vendors/echarts/map/js/china.js"></script>
    <script type="text/javascript" src="https://api.map.baidu.com/api?v=2.0&ak=你的ak"></script>
    <script type="text/javascript">
    $(function () {
        $.ajax({
            type:'post',
            url:'/query',
            dataType:'json',
            success:function (returnData) {
                console.log(returnData);
                if (returnData.status == 1){
                    option = {
                        title: {
                            text: '大数据行业地点与薪资关系',
                            subtext: 'Test数据',
                            left: 'center'
                        },
                        tooltip: {
                            trigger: 'item',
                            formatter: function(params) {
                                            var res = params.name+'<br/>';
                                            var myseries = option.series;
                                            for (var i = 0; i < myseries.length; i++) {
                                                for(var j=0;j<myseries[i].data.length;j++){
                                                    if(myseries[i].data[j].name==params.name){
                                                        res+=myseries[i].name +' : '+myseries[i].data[j].value+'</br>';
                                                    }
                                                }
                                            }
                                            return res;
                                        }
                        },
                        legend: {
                            orient: 'vertical',
                            left: 'left',
                            data:['最大薪资(k)','最低薪资(k)','平均薪资(k)','总职位数(个)']
                        },
                        visualMap: {
                            min: 0,
                            max: 200,
                            left: 'left',
                            top: 'bottom',
                            text: ['高','低'],           // 文本,默认为数值文本
                            calculable: true
                        },
                        toolbox: {
                            show: true,
                            orient: 'vertical',
                            left: 'right',
                            top: 'center',
                            feature: {
                                dataView: {readOnly: false},
                                restore: {},
                                saveAsImage: {}
                            }
                        },
                        series: [
                            {
                                name: '最大薪资(k)',
                                type: 'map',
                                mapType: 'china',
                                roam: false,
                                tooltip:{
                                    show:true
                                },
                                label: {
                                    normal: {
                                        show: true
                                    },
                                    emphasis: {
                                        show: true
                                    }
                                },
                                data:returnData.max_salary
                            },
                            {
                                name: '最低薪资(k)',
                                type: 'map',
                                mapType: 'china',
                                 tooltip:{
                                    show:true
                                },
                                label: {
                                    normal: {
                                        show: true
                                    },
                                    emphasis: {
                                        show: true
                                    }
                                },
                                data:returnData.min_salary

                            },
                            {
                                name: '平均薪资(k)',
                                type: 'map',
                                mapType: 'china',
                                 tooltip:{
                                    show:true
                                },
                                label: {
                                    normal: {
                                        show: true
                                    },
                                    emphasis: {
                                        show: true
                                    }
                                },
                                data:returnData.avg_salary
                            },   {
                                name: '总职位数(个)',
                                type: 'map',
                                mapType: 'china',
                                 tooltip:{
                                    show:true
                                },
                                label: {
                                    normal: {
                                        show: true
                                    },
                                    emphasis: {
                                        show: true
                                    }
                                },
                                data:returnData.count_job
                            }
                        ]
                    };
                }
                    var dom = document.getElementById("container");
                    var myChart = echarts.init(dom);
                    myChart.setOption(option);
                                }
                            })
                        });
    </script>

</body>

</html>

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转载自blog.csdn.net/qq_42844049/article/details/88364254