peewee快速使用

示例

模型定义和Django、SQLAlchemy类似

Python

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

from peewee import *

from playhouse.sqlite_ext import SqliteExtDatabase

import datetime

 

db = SqliteExtDatabase('my_database.db')

 

class BaseModel(Model):

    class Meta:

        database = db

 

class User(BaseModel):

    username = CharField(unique=True)

 

class Tweet(BaseModel):

    user = ForeignKeyField(User, related_name='tweets')

    message = TextField()

    created_date = DateTimeField(default=datetime.datetime.now)

    is_published = BooleanField(default=True)

连接到数据库并创建表格和添加数据

Python

1

2

3

4

5

6

7

8

9

10

db.connect()

db.create_tables([User,Tweet])

 

charlie=User.create(username='charlie')

huey=User(username='huey')

huey.save()

 

# No need to set `is_published` or `created_date` since they

# will just use the default values we specified.

Tweet.create(user=charlie,message='My first tweet')

查询

Python

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

# A simple query selecting a user.

User.get(User.username=='charles')

 

# Get tweets created by one of several users. The "<<" operator

# corresponds to the SQL "IN" operator.

usernames=['charlie','huey','mickey']

users=User.select().where(User.username<<usernames)

tweets=Tweet.select().where(Tweet.user<<users)

 

# We could accomplish the same using a JOIN:

tweets=(Tweet

          .select()

          .join(User)

          .where(User.username<<usernames))

 

# How many tweets were published today?

tweets_today=(Tweet

                .select()

                .where(

                    (Tweet.created_date>=datetime.date.today())&

                    (Tweet.is_published==True))

                .count())

 

# Paginate the user table and show me page 3 (users 41-60).

User.select().order_by(User.username).paginate(3,20)

 

# Order users by the number of tweets they've created:

tweet_ct=fn.Count(Tweet.id)

users=(User

        .select(User,tweet_ct.alias('ct'))

        .join(Tweet,JOIN.LEFT_OUTER)

        .group_by(User)

        .order_by(tweet_ct.desc()))

 

# Do an atomic update

Counter.update(count=Counter.count+1).where(

    Counter.url==request.url)

官方网站：http://docs.peewee-orm.com/en/latest/index.html#
开源地址：https://github.com/coleifer/peewee