前提:
准备Python + Flask+Sqlite3的平台环境(windows系统)
前面一节介绍flask怎么安装了,剩下sqlite3下载后解压,然后环境变量添加解压路径就行了
附加下载地址:http://www.sqlite.org/2016/sqlite-tools-win32-x86-3150200.zip
项目的目录结构
/www
|
|-- /static
| |jquery-1.6.2.js (可以是其他jquery-xx.js,在index.html里修改就行了)
| |-- echarts.js(还有echarts原dist目录下的文件(夹))
|
|-- /templates
| |
| |-- index.html
|
|-- app.py
|
|-- create_db.py
记得下载:echarts,echarts包含:
# create_db.py
# 只运行一次!!! import sqlite3 # 连接
conn = sqlite3.connect('mydb.db')
c = conn.cursor() # 创建表
c.execute('''DROP TABLE IF EXISTS weather''')
c.execute('''CREATE TABLE weather (month text, evaporation text, precipitation text)''') # 数据
# 格式:月份,蒸发量,降水量
purchases = [(1, 2, 2.6),
(2, 4.9, 5.9),
(3, 7, 9),
(4, 23.2, 26.4),
(5, 25.6, 28.7),
(6, 76.7, 70.7),
(7, 135.6, 175.6),
(8, 162.2, 182.2),
(9, 32.6, 48.7),
(10, 20, 18.8),
(11, 6.4, 6),
(12, 3.3, 2.3)
] # 插入数据
c.executemany('INSERT INTO weather VALUES (?,?,?)', purchases) # 提交!!!
conn.commit() # 查询方式一
for row in c.execute('SELECT * FROM weather'):
print(row) # 查询方式二
c.execute('SELECT * FROM weather')
print(c.fetchall()) # 查询方式二_2
res = c.execute('SELECT * FROM weather')
print(res.fetchall()) # 关闭
conn.close()
建立数据库结果:
// index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>ECharts Ajax</title>
<script src="{{ url_for('static', filename='jquery-1.6.2.js') }}"></script>
</head> <body>
<!--Step:1 为ECharts准备一个具备大小(宽高)的Dom-->
<div id="main" style="height:500px;border:1px solid #ccc;padding:10px;"></div> <!--Step:2 引入echarts.js-->
<!--<script src="js/echarts.js"></script>-->
<script src="{{ url_for('static', filename='echarts.js') }}"></script> <script type="text/javascript">
// Step:3 为模块加载器配置echarts的路径,从当前页面链接到echarts.js,定义所需图表路径
require.config({
paths: {
echarts: './static',
}
}); // Step:4 动态加载echarts然后在回调函数中开始使用,注意保持按需加载结构定义图表路径
require(
[
'echarts',
'echarts/chart/bar', // 按需加载
'echarts/chart/line',
],
function (ec) {
//--- 折柱 ---
var myChart = ec.init(document.getElementById('main')); // 设置---------------------
var option = {
tooltip : {
trigger: 'axis'
},
legend: {
data:['蒸发量','降水量']
},
toolbox: {
show : true,
feature : {
mark : {show: true},
dataView : {show: true, readOnly: false},
magicType : {show: true, type: ['line', 'bar']},
restore : {show: true},
saveAsImage : {show: true}
}
},
calculable : true,
xAxis : [
{
type : 'category',
data : []
}
],
yAxis : [
{
type : 'value',
splitArea : {show : true}
}
],
series : [
{
name:'蒸发量',
type:'bar',
data:[]
},
{
name:'降水量',
type:'line',
data:[]
}
]
}; $.ajax({
cache: false,
type: "POST",
url: "/weather", //把表单数据发送到/weather
data: null, // 发送的数据
dataType : "json", //返回数据形式为json
async: false,
error: function(request) {
alert("发送请求失败!");
},
success: function(result) {
//console.log(result);
for (i = 0, max = result.month.length; i < max; i++) { //注意:result.month.length
option.xAxis[0].data.push(result.month[i]);
option.series[0].data.push(parseFloat(result.evaporation[i]));
option.series[1].data.push(parseFloat(result.precipitation[i]));
}; // 为echarts对象加载数据--------------
myChart.setOption(option);
}
});
// 为echarts对象加载数据--------------
//myChart.setOption(option);
}
);
</script>
</body>
</html>
# app.py import sqlite3
from flask import Flask, request, render_template, jsonify app = Flask(__name__) def get_db():
db = sqlite3.connect('mydb.db')
db.row_factory = sqlite3.Row
return db def query_db(query, args=(), one=False):
db = get_db()
cur = db.execute(query, args)
db.commit()
rv = cur.fetchall()
db.close()
return (rv[0] if rv else None) if one else rv @app.route("/", methods=["GET"])
def index():
return render_template("index.html") @app.route("/weather", methods=["POST"])
def weather():
if request.method == "POST":
res = query_db("SELECT * FROM weather") return jsonify(month = [x[0] for x in res],
evaporation = [x[1] for x in res],
precipitation = [x[2] for x in res]) if __name__ == "__main__":
app.run(debug=True)
运行后:
打开:http://127.0.0.1:5000/