在Python的框架中為MySQL實現(xiàn)restful接口的教程

更新時間：2015年04月08日 17:33:25 作者：vimer

這篇文章主要介紹了在Python的框架中為MySQL實現(xiàn)restful接口的教程,文中的示例基于Flask和Django框架,需要的朋友可以參考下

最近在做游戲服務(wù)分層的時候，一直想把mysql的訪問獨立成一個單獨的服務(wù)DBGate，原因如下:

請求收攏到DBGate，可以使DBGate變?yōu)闊o狀態(tài)的，方便橫向擴展
當(dāng)請求量或者存儲量變大時，mysql需要做分庫分表，DBGate可以內(nèi)部直接處理，外界無感知
通過restful限制對數(shù)據(jù)請求的形式，僅支持簡單的get/post/patch/put 進行增刪改查，并不支持復(fù)雜查詢。這個也是和游戲業(yè)務(wù)的特性有關(guān)，如果網(wǎng)站等需要復(fù)雜查詢的業(yè)務(wù)，對此并不適合
DBGate使用多進程模式，方便控制與mysql之間的鏈接數(shù)，進行mysql訪問量閥值保護
方便在DBGate上進行訪問量統(tǒng)計，慢查詢統(tǒng)計、權(quán)限控制等等一系列邏輯
目前是使用python，以后要使用其他語言進行mysql操作時，只要進行標(biāo)準(zhǔn)的http請求即可，不會出現(xiàn)不兼容的情況

當(dāng)然壞處也是有的：

首當(dāng)其沖就是單次請求的響應(yīng)時間變長，畢竟中間加了一層服務(wù)，并且還是http格式
部署上比原來復(fù)雜了一些，很多對mysql直接操作的思維需要進行轉(zhuǎn)變，一開始可能會有些不適

不過總的來說，還是利大于弊，所以最終還是決定搭建DBGate

當(dāng)然，我們不可能去手工挨個寫每個庫表對應(yīng)的restful服務(wù)，值得慶幸的是django和flask都提供了對應(yīng)的解決方案，我們一個個介紹.
Flask

參考鏈接: flask-restless

flask-restless使用方法比較簡單，我直接貼一下代碼即可:

# -*- coding: utf-8 -*-

import datetime
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_restless import APIManager

app = Flask(__name__)
db = SQLAlchemy(app)
restless = APIManager(app, flask_sqlalchemy_db=db)

class User(db.Model):
    """
    user
    """

    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(255), unique=True, nullable=False)
    password = db.Column(db.String(255), nullable=False)
    create_time = db.Column(db.DateTime, nullable=False, default=datetime.datetime.utcnow)
    login_time = db.Column(db.DateTime)

restless.create_api(User, methods=['GET', 'POST', 'DELETE', 'PATCH', 'PUT'], results_per_page=100)

db.create_all()

if __name__ == '__main__':
    app.run(port=25000)

# -*- coding: utf-8 -*-

import datetime
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_restless import APIManager

app = Flask(__name__)
db = SQLAlchemy(app)
restless = APIManager(app, flask_sqlalchemy_db=db)

class User(db.Model):
    """
    user
    """

    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(255), unique=True, nullable=False)
    password = db.Column(db.String(255), nullable=False)
    create_time = db.Column(db.DateTime, nullable=False, default=datetime.datetime.utcnow)
    login_time = db.Column(db.DateTime)

restless.create_api(User, methods=['GET', 'POST', 'DELETE', 'PATCH', 'PUT'], results_per_page=100)

db.create_all()

if __name__ == '__main__':
    app.run(port=25000)

其對應(yīng)的restful操作如下:

獲取用戶列表:   GET /user
添加用戶:       POST /user
獲取單個用戶:   GET /user/1
覆蓋單個用戶:   PUT /user/1
修改單個用戶:   PATCH /user/1

注意:

在http請求中，記得加入header: Content-Type: application/json
flask-restless中，PUT和PATCH一樣，都是傳入什么字段，只修改什么字段，不會完全覆蓋

Django

參考鏈接: Django REST framework

Django用起來要更復(fù)雜一些，也因為django版自帶了一個可視化的操作頁面，如下:

201548172936523.png (600×545)

1. 在settings中添加:

REST_FRAMEWORK = {
  # Use hyperlinked styles by default.
  # Only used if the `serializer_class` attribute is not set on a view.
  'DEFAULT_MODEL_SERIALIZER_CLASS':
    'rest_framework.serializers.HyperlinkedModelSerializer',

  # Use Django's standard `django.contrib.auth` permissions,
  # or allow read-only access for unauthenticated users.
  'DEFAULT_PERMISSION_CLASSES': [
    #'rest_framework.permissions.DjangoModelPermissionsOrAnonReadOnly',
    'rest_framework.permissions.IsAdminUser',
  ]
}
 
REST_FRAMEWORK = {
  # Use hyperlinked styles by default.
  # Only used if the `serializer_class` attribute is not set on a view.
  'DEFAULT_MODEL_SERIALIZER_CLASS':
    'rest_framework.serializers.HyperlinkedModelSerializer',
 
  # Use Django's standard `django.contrib.auth` permissions,
  # or allow read-only access for unauthenticated users.
  'DEFAULT_PERMISSION_CLASSES': [
    #'rest_framework.permissions.DjangoModelPermissionsOrAnonReadOnly',
    'rest_framework.permissions.IsAdminUser',
  ]
}

2. 通過startapp建立一個app: demo
3. 修改demo的models:

class User(models.Model):
  # key是保留字
  password = models.IntegerField()
  nick = models.CharField(max_length=255)
  create_time = models.DateTimeField(default=datetime.datetime.now)
 
class User(models.Model):
  # key是保留字
  password = models.IntegerField()
  nick = models.CharField(max_length=255)
  create_time = models.DateTimeField(default=datetime.datetime.now)

4. 在demo下新建serializers.py

from rest_framework import serializers
from models import User
class UserSerializer(serializers.ModelSerializer):
  class Meta:
    model = User
 
from rest_framework import serializers
from models import User
 
 
class UserSerializer(serializers.ModelSerializer):
  class Meta:
    model = User

5. 在demo下修改views.py

from django.shortcuts import render
from rest_framework import viewsets

from serializers import UserSerializer
from models import User


class UserViewSet(viewsets.ModelViewSet):
  queryset = User.objects.all()
  serializer_class = UserSerializer
 
from django.shortcuts import render
from rest_framework import viewsets
 
from serializers import UserSerializer
from models import User
 
 
class UserViewSet(viewsets.ModelViewSet):
  queryset = User.objects.all()
  serializer_class = UserSerializer

6. 在demo下新建urls.py

import os.path
from django.conf.urls import patterns, include, url
from django.conf.urls.static import static
from django.conf import settings
import views

from rest_framework import routers

appname = os.path.basename(os.path.dirname(os.path.abspath(__file__)))

router = routers.DefaultRouter()
router.register('users', views.UserViewSet, appname)

urlpatterns = patterns('',
            url(r'^', include(router.urls)),
)
 
import os.path
from django.conf.urls import patterns, include, url
from django.conf.urls.static import static
from django.conf import settings
import views
 
from rest_framework import routers
 
appname = os.path.basename(os.path.dirname(os.path.abspath(__file__)))
 
router = routers.DefaultRouter()
router.register('users', views.UserViewSet, appname)
 
urlpatterns = patterns('',
            url(r'^', include(router.urls)),
)

7. 在mysite.urls下include demo.urls和rest_framework.urls

urlpatterns = patterns('',
  url(r'^demo/', include('demo.urls')),
  url(r'^admin/', include(admin.site.urls)),
  url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
)
 
urlpatterns = patterns('',
  url(r'^demo/', include('demo.urls')),
  url(r'^admin/', include(admin.site.urls)),
  url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
)

8. 執(zhí)行初始化數(shù)據(jù)操作:

python manage.py syncdb
 
python manage.py syncdb

之后訪問: http://127.0.0.1:8000/demo 即可看到如下界面了:

201548173034739.png (600×353)

對應(yīng)的測試代碼如下:

import json
import requests
from urlparse import urljoin

BASE_URL = 'http://127.0.0.1:16500/'
AUTH = ('admin', 'admin')


def test_get_user_list():
  rsp = requests.get(urljoin(BASE_URL, '/demo/users/'), auth=AUTH, headers={
    'Accept': 'application/json'
  })
  assert rsp.ok


def test_post_user_list():
  json_data = dict(
    password=0,
    nick='oo',
    create_time='2014-03-3T03:3:3'
  )
  rsp = requests.post(urljoin(BASE_URL, '/demo/users/'), auth=AUTH, headers={
    'Accept': 'application/json',
    'Content-Type': 'application/json',
  }, data=json.dumps(json_data))
  assert rsp.ok


def test_get_user():
  rsp = requests.get(urljoin(BASE_URL, '/demo/users/1'), auth=AUTH, headers={
    'Accept': 'application/json',
    'Content-Type': 'application/json',
  })
  assert rsp.ok


def test_put_user():
  json_data = dict(
    password=100,
    nick='xx',
    create_time='2014-03-3T03:3:3'
  )
  # 注意最后的 /
  rsp = requests.put(urljoin(BASE_URL, '/demo/users/1/'), auth=AUTH, headers={
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    }, data=json.dumps(json_data),
  )
  assert rsp.ok, rsp.status_code

Django REST framework 是嚴(yán)格區(qū)分PUT和PATCH的，這一點和flask-restless 不一樣，需要注意。

OK，就這樣。

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