在Python的框架中為MySQL實(shí)現(xiàn)restful接口的教程

2019-11-25 17:47:41

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最近在做游戲服務(wù)分層的時(shí)候，一直想把mysql的訪問(wèn)獨(dú)立成一個(gè)單獨(dú)的服務(wù)DBGate，原因如下:

請(qǐng)求收攏到DBGate，可以使DBGate變?yōu)闊o(wú)狀態(tài)的，方便橫向擴(kuò)展
當(dāng)請(qǐng)求量或者存儲(chǔ)量變大時(shí)，mysql需要做分庫(kù)分表，DBGate可以內(nèi)部直接處理，外界無(wú)感知
通過(guò)restful限制對(duì)數(shù)據(jù)請(qǐng)求的形式，僅支持簡(jiǎn)單的get/post/patch/put 進(jìn)行增刪改查，并不支持復(fù)雜查詢。這個(gè)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(duì)此并不適合
DBGate使用多進(jìn)程模式，方便控制與mysql之間的鏈接數(shù)，進(jìn)行mysql訪問(wèn)量閥值保護(hù)
方便在DBGate上進(jìn)行訪問(wèn)量統(tǒng)計(jì)，慢查詢統(tǒng)計(jì)、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(yǔ)言進(jìn)行mysql操作時(shí)，只要進(jìn)行標(biāo)準(zhǔn)的http請(qǐng)求即可，不會(huì)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(qǐng)求的響應(yīng)時(shí)間變長(zhǎng)，畢竟中間加了一層服務(wù)，并且還是http格式
部署上比原來(lái)復(fù)雜了一些，很多對(duì)mysql直接操作的思維需要進(jìn)行轉(zhuǎn)變，一開(kāi)始可能會(huì)有些不適

不過(guò)總的來(lái)說(shuō)，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(gè)寫(xiě)每個(gè)庫(kù)表對(duì)應(yīng)的restful服務(wù)，值得慶幸的是django和flask都提供了對(duì)應(yīng)的解決方案，我們一個(gè)個(gè)介紹.
Flask

參考鏈接: flask-restless

flask-restless使用方法比較簡(jiǎn)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(duì)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(gè)用戶:   GET /user/1
覆蓋單個(gè)用戶:   PUT /user/1
修改單個(gè)用戶:   PATCH /user/1

注意:

在http請(qǐng)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(huì)完全覆蓋

Django

參考鏈接: Django REST framework

Django用起來(lái)要更復(fù)雜一些，也因?yàn)閐jango版自帶了一個(gè)可視化的操作頁(yè)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(guò)startapp建立一個(gè)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 serializersfrom models import User  class UserSerializer(serializers.ModelSerializer):  class Meta:    model = User

5. 在demo下修改views.py

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

6. 在demo下新建urls.py

import os.pathfrom django.conf.urls import patterns, include, urlfrom django.conf.urls.static import staticfrom django.conf import settingsimport viewsfrom rest_framework import routersappname = 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.pathfrom django.conf.urls import patterns, include, urlfrom django.conf.urls.static import staticfrom django.conf import settingsimport 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(wèn): http://127.0.0.1:8000/demo 即可看到如下界面了:

201548173034739.png (600×353)

對(duì)應(yīng)的測(cè)試代碼如下:

import jsonimport requestsfrom urlparse import urljoinBASE_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.okdef 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.okdef test_get_user():  rsp = requests.get(urljoin(BASE_URL, '/demo/users/1'), auth=AUTH, headers={    'Accept': 'application/json',    'Content-Type': 'application/json',  })  assert rsp.okdef 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(diǎn)和flask-restless 不一樣，需要注意。

OK，就這樣。

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