Python拥有对SQlite的内置支持。 SQlite3模块随附Python发行版。在本节中，我们将看到Flask应用程序如何与SQLite进行交互。
创建一个SQLite数据库 ‘database.db’并在其中创建一个student表。
示例
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08import sqlite3 conn = sqlite3.connect('database.db') print "Opened database successfully"; conn.execute('CREATE TABLE students (name TEXT, addr TEXT, city TEXT, pin TEXT)') print "Table created successfully"; conn.close()Flask应用程序有三个视图函数。
第一个new_student()函数绑定到URL规则(‘/addnew’)。 它呈现包含学生信息表单的HTML文件。
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08@app.route('/enternew') def new_student(): return render_template('student.html')‘student.html’的HTML脚本如下 -
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08 Flask示例 可以看出，表单数据发布到绑定addrec()函数，对应于URL => ‘/addrec’ 。
这个addrec()函数通过POST方法检索表单的数据并插入到学生表中。 与插入操作中的成功或错误相对应的消息呈现为’result.html’。
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08@app.route('/addrec',methods = ['POST', 'GET']) def addrec(): if request.method == 'POST': try: nm = request.form['nm'] addr = request.form['add'] city = request.form['city'] pin = request.form['pin'] with sql.connect("database.db") as con: cur = con.cursor() cur.execute("INSERT INTO students (name,addr,city,pin) VALUES (?,?,?,?)",(nm,addr,city,pin) ) con.commit() msg = "Record successfully added" except: con.rollback() msg = "error in insert operation" finally: return render_template("result.html",msg = msg) con.close()result.html 的HTML脚本包含显示插入操作结果的转义语句{{msg}}。
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08 Flask示例 操作结果 : {{ msg }} 返回主页
该应用程序包含由URL => ‘/list’表示的另一个list()函数。 它将“行”填充为包含学生表中所有记录的MultiDict对象。 这个对象传递到 list.html 模板。
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08@app.route('/list') def list(): con = sql.connect("database.db") con.row_factory = sql.Row cur = con.cursor() cur.execute("select * from students") rows = cur.fetchall(); return render_template("list.html",rows = rows)这个list.html是一个模板，它遍历行集合并在HTML表格中呈现数据。
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08 Flask示例 改名 地址 城市 编码 {% for row in rows %} {{row["name"]}} {{row["addr"]}} {{row["city"]}} {{row['pin']}} {% endfor %}
返回主页 最后，URL => ‘/‘规则呈现一个’home.html’作为应用程序的入口点。
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08@app.route('/') def home(): return render_template('home.html')这里是Flask-SQLite应用程序的完整代码。
示例
# Filename : example.py# Copyright : 2020 By Nhooo# Author by : www.cainiaojc.com# Date : 2020-08-08from flask import Flask, render_template, request import sqlite3 as sql import sqlite3 app = Flask(__name__) @app.route('/') def home(): return render_template('home.html') @app.route('/enternew') def new_student(): return render_template('student.html') @app.route('/addrec',methods = ['POST', 'GET']) def addrec(): if request.method == 'POST': try: nm = request.form['nm'] addr = request.form['add'] city = request.form['city'] pin = request.form['pin'] with sql.connect("database.db") as con: cur = con.cursor() cur.execute("INSERT INTO students (name,addr,city,pin) VALUES (?,?,?,?)",(nm,addr,city,pin) ) con.commit() msg = "Record successfully added" except: con.rollback() msg = "error in insert operation" finally: return render_template("result.html",msg = msg) con.close() @app.route('/list') def list(): con = sql.connect("database.db") con.row_factory = sql.Row cur = con.cursor() cur.execute("select * from students") rows = cur.fetchall(); return render_template("list.html",rows = rows) @app.route('/init') def init(): conn = sqlite3.connect('database.db') print ("Opened database successfully") conn.execute('CREATE TABLE students (name TEXT, addr TEXT, city TEXT, pin TEXT)') print ("Table created successfully") conn.close() return None if __name__ == '__main__': app.run(debug = True)从Python shell运行此脚本，并在开发服务器开始运行时运行。 访问:http:// localhost:5000/ 在浏览器中显示一个这样的简单菜单 -
点击 “添加学生信息” 链接打开添加学生信息表单。
填写表单并提交。底层函数将该记录插入到学生表中。
返回主页并点击“显示列表”链接，将显示样本数据的表格。
| 留言与评论（共有 0 条评论） “” |
