1.1.1 安装

pip install peewee
pip install pymysql
pip install cryptography

1.1.2 定义表结构

# 1. 定义并生成表
import datetime
from peewee import *
db = MySQLDatabase('peewee', host='127.0.0.1', user='root', passwd='root');
class User(Model):
    username = CharField(unique=True)
    class Meta:
        database = db
class Tweet(Model):
    user = ForeignKeyField(User, backref='tweets')
    message = TextField()
    created_date = DateTimeField(default=datetime.datetime.now)
    is_published = BooleanField(default=True)
    class Meta:
        database = db

1.1.3 生成数据表

    db.connect()
    db.create_tables([User, Tweet])

1.1.4 添加/更新/删除/查询

    # 2.添加
    # charlie = User(username="charlie")  # update set age = 18 where username ="charlie"
    # rows = charlie.save()
    # if rows == 0:
    #     print("未更新数据")
    # charlie.save(force_insert=True)  # 1.save方法既可以完成新建. 也可以完成更新的操作（你的对象钟主键值是否有设置你是一个更新的操作）
    # huey = User.create(username="huey")
    # 3.查询
    # 3.1 get方法
    #   1.返回回来的是直接的user对象
    #   2.这个方法如果查询不到会抛出异常
    try:
        # charlie = User.get(User.username == "charlie")
        charlie = User.get_by_id("chalie")
        print(charlie.username)
    # 这个操作发起的sql请求是什么
    except User.DoesNotExist as e:
        print("查询不到")
    # 3.2 select操作 查询所有
    # users = User.select()
    #   1.没有看到sql查询语句,用于组装sql
    #   2.对象是 ModelSelect 对象 我们对 ModelSelect 进行for循环和切片的时候才会发起请求
    # print(users.sql())
    # print(type(users))
    # user = users[0]
    # print(type(user))
    # usernames = ["charlie", "huey", "mickey"]
    # users = User.select().where(User.username.in_(usernames))
    # for user in users:
    #     print(user.username)
    # for user in User.select():
    #     print(user.username)
    # 更新
    charlie = User(username="charld2ie")  # update set xx=xx where username="charlie"
    print(charlie.save())
    # 使用update更新
    print(User.update(age=15).where(User.username == "charlie").execute())
    # 删除数据
    user = User.get(User.username == "charld2ie")
    user.delete_instance()

1.1.5 解决peewee的warning