这次是数据库使用，拒绝花哨主打就是一个简单
pip install flask-sqlalchemy
调用数据库现在配置里边设置下然后绑上APP后，定义数据结构类.下面是我认为最简单的数据库增删查改结构。
from flask_sqlalchemy import SQLAlchemy
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///db.sqlite3'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
db = SQLAlchemy(app)
##定义数据结构类
class User(db.Model):id = db.Column(db.Integer, primary_key=True)username = db.Column(db.String(80), unique=True, nullable=False)email = db.Column(db.String(120), unique=True, nullable=False)def __repr__(self):return '<User %r>' % self.username
## 如果没有表要创建表，有的话则无改动
with app.app_context():db.create_all()
##查询数据
@app.route("/sql")
def find_all_users():users = User.query.all()print(users)return render_template("sql.html", users=users)
##查询一个数据
@app.route("/get/<int:get_id>")
def get_by_id(get_id):get_user = User.query.get(get_id) # User.query.filter_by(id=get_id).first()return "编号：{0}，用戶名：{1}，邮箱：{2}".format(get_user.id, get_user.username, get_user.email)
##增加数据
@app.route("/add/<username>")
def add_user(username):new_user = User()new_user.username = usernamenew_user.email = username + "@qq.com"db.session.add(new_user)db.session.commit()return redirect("/")
##删除数据
@app.route("/delete/<int:del_id>")
def delete_by_id(del_id):del_user = User.query.filter_by(id=del_id).first()if del_user is not None:db.session.delete(del_user)db.session.commit()return redirect("/")@app.route("/update", methods=["GET", "POST"])
def update():if request.method == "POST":user_id = request.form.get("id")new_username = request.form.get("username")new_email = request.form.get("email")user = User.query.get(user_id)if user:user.username = new_usernameuser.email = new_emaildb.session.commit()return redirect(url_for("update"))users = User.query.all()return render_template("update.html", users=users)
sql.html
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<table border="1"><tr><th>编号</th><th>用户名</th><th>邮箱</th><th>操作</th></tr>{% for u in users %}<tr><td>{{ u.id }}</td><td>{{ u.username }}</td><td>{{ u.email }}</td><td><a href="delete/{{ u.id }}">删除</a></td></tr>{% endfor %}
</table>update.html
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Update User</title>
</head>
<body><table border="1"><tr><th>编号</th><th>用户名</th><th>邮箱</th></tr>{% for u in users %}<tr><td>{{ u.id }}</td><td>{{ u.username }}</td><td>{{ u.email }}</td></tr>{% endfor %}</table><h2>更新用户信息</h2><form action="/update" method="post"><label for="id">用户ID:</label><br><input type="text" id="id" name="id" required><br><label for="username">新用户名:</label><br><input type="text" id="username" name="username" required><br><label for="email">新邮箱:</label><br><input type="email" id="email" name="email" required><br><input type="submit" value="更新"></form>
</body>
</html>补充内容数据迁移
安装
pip install flask-migrate
app 里边进行注册和绑定
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy(app)
from flask_migrate import Migrate
migrate =Migrate(app,db)
类似GIT的版本控制。流程为初始化（只执行一次）==》构建迁移脚本=》迁移
flask db init
flask db migrate
flask db upgrade
