tornado是一个异步web框架，其中不能使用阻塞的操作，不然会导致整个程序的阻塞。数据库操作时不可避免的需要使用，这里采用的是peewee-async去解决。
peewee-async 是一个为 peewee orm框架提供异步接口的库。
该项目的github地址: tornado_learning.git (opens new window)
在settings.py文件中创建连接数据库
代码: server.py
import peewee_async
database = peewee_async.MySQLDatabase("tornado_learning", "127.0.0.1", port=3306, user="root", password="root1234")
1
2
3
在server.py中引用数据库连接，并加入到app中
from peewee_async import Manager
from tornado import web, ioloop
from tornado_learning.settings import database
from tornado_learning.settings import settings
from tornado_learning.urls import urlpattern
def make_app():
app = web.Application(urlpattern, debug=True, **settings)
# 就在这里添加数据库连接
objects = Manager(database)
# 禁止使用同步操作
database.set_allow_sync(False)
app.objects = objects
return app
if __name__ == '__main__':
app = make_app()
app.listen(8888)
ioloop.IOLoop.current().start()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
创建通用的BaseModel类
create_time是每个model都需要的字段，将两个字段提取到BaseModel中。
id字段在peewee中会为每个model自动创建。
为每一个model指定database
在配置目录tornado_learning中创建model.py
代码: tornado_learning/models
from datetime import datetime
from peewee import Model, DateTimeField
from tornado_learning.settings import database
class BaseModel(Model):
create_time = DateTimeField(default=datetime.now, verbose_name="创建时间")
class Meta:
database = database
1
2
3
4
5
6
7
8
9
10
创建model类
这里的student和teacher的关系是1对多。
创建student的模型类。
代码: apps/school/models.py
from peewee import CharField, IntegerField, TextField
from tornado_learning.models import BaseModel
class Student(BaseModel):
name = CharField(max_length=100, null=False, verbose_name="学生名")
age = IntegerField(null=False, verbose_name="年龄")
desc = TextField(verbose_name="个人简介")
1
2
3
4
5
6
7
创建teacher的模型类
class Teacher(BaseModel):
student = ForeignKeyField(rel_model=Student, related_name="teachers")
name = CharField(max_length=100, null=False, verbose_name="老师名")
age = IntegerField(null=False, verbose_name="年龄")
subject = CharField(max_length=100, null=False, verbose_name="学科")
1
2
3
4
5
使用工具类创建表
在tools/init_db.py中初始化表。
运行该文件即可在数据库中创建表
from tornado_learning.settings import database
from apps.school.models import Student
def init_db():
database.create_tables([Student, student])
if __name__ == '__main__':
init_db()
1
2
3
4
5
6
7
8
下面是增删改查的例子。
form表单的使用可以参考我的文章<<tornado 结合wtforms使用表单操作
代码: apps/school/handler.py
import tornado
from apps.school.forms import StudentForm
from apps.school.models import Student
from tornado_learning.handler import BaseHandler
class StudentHandler(BaseHandler):
async def get(self):
id = self.get_argument("id", None)
if not id:
return self.write("please provide the 'id'")
student = await self.application.objects.get(Student, id=id)
try:
self.write({
"id": student.id,
"name": student.name
})
except Student.DoesNotExist:
raise tornado.webHttpError(404, "Object not found")
async def post(self):
student_form = StudentForm(self.request.arguments)
if student_form.validate():
await self.application.objects.create(Student, **student_form.data)
self.write("创建成功")
else:
self.write("校验失败")
async def delete(self):
id = self.get_argument("id", None)
if not id:
return self.write("please provide the 'id'")
student = await self.application.objects.get(Student, id=id)
await self.application.objects.delete(student)
self.write("删除成功")
async def put(self):
studentForm = StudentForm(self.request.arguments)
student = Student(**studentForm.data)
if studentForm.validate():
await self.application.objects.update(student)
self.write("更新成功")
else:
print(studentForm.errors)
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
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
在teacher model中添加extend方法，拼凑连表查询的方法，方便使用。
代码: apps/school/model.py
class Teacher(BaseModel):
student = ForeignKeyField(rel_model=Student, related_name="teachers")
name = CharField(max_length=100, null=False, verbose_name="老师名")
age = IntegerField(null=False, verbose_name="年龄")
subject = CharField(max_length=100, null=False, verbose_name="学科")
@classmethod
def extend(cls):
return cls.select(cls, Student.name, Student.age).join(Student)
1
2
3
4
5
6
7
8
9
使用peewee拼凑出查询，然后通过异步执行得到结果
代码: apps/school/handler.py
class TeacherHandler(BaseHandler):
async def get(self):
ret_data = {"data": []}
teacher_query = Teacher.extend()
teacher_query = teacher_query.filter(Teacher.age > 20)
teachers = await self.application.objects.execute(teacher_query)
for teacher in teachers:
item_dict = {
"teacher_name": teacher.name,
"teacher_age": teacher.age,
"student_name": teacher.student.name,
"student_age": teacher.student.age
}
ret_data['data'].append(item_dict)
return self.finish(ret_data)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
此内容由惯性聚合(RSS阅读器)自动聚合整理，仅供阅读参考。 原文来自 — 版权归原作者所有。