一、開發環境

1、python3.6

2、django2.0

3、window10

二、項目搭建

1、創建一個虛擬空間mkvirtualenv 空間名

2、創建一個django項目

3、安裝graphql的依賴包

pip install graphene-django

4、創建一個組件blog

5、把組件blog及graphene_django注入到app中

6、在settings.py中配置mysql數據庫連接

三、書寫blog的內容

1、在models.py中寫上數據模型

from django.db import models# Create your models here.class User(models.Model): name = models.CharField(max_length=100, verbose_name='博主名字') gender = models.CharField(max_length=6, choices=((’male’, u’男’), (’female’, ’女’)), default=’female’,verbose_name=’性別’) create_at = models.DateTimeField(auto_now_add=True, verbose_name=’創建時間’)class Blog(models.Model): title = models.CharField(max_length=100, verbose_name=’標題’) user = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL, verbose_name=’博主名字’) content = models.TextField(verbose_name=’博客內容’) create_at = models.DateTimeField(auto_now_add=True, verbose_name=’創建時間’) update_at = models.DateTimeField(auto_now=True, verbose_name=’更新時間’)

2、新建一個schema.py文件

#!/usr/bin/env python# encoding: utf-8import graphenefrom graphene_django.types import DjangoObjectTypefrom .models import User, Blogclass UserType(DjangoObjectType): class Meta: model = Userclass BlogType(DjangoObjectType): class Meta: model = Blog# 定義動作約素輸入類型class UserInput(graphene.InputObjectType): name = graphene.String(required=True) gender = graphene.String(required=True)class BlogInput(graphene.InputObjectType): title = graphene.String(required=True) user = graphene.Int(required=True) content = graphene.String(required=True)# 定義一個創建user的mutationclass CreateUser(graphene.Mutation): # api的輸入參數 class Arguments: user_data = UserInput(required=True) # api的響應參數 ok = graphene.Boolean() user = graphene.Field(UserType) # api的相應操作，這里是create def mutate(self, info, user_data): user = User.objects.create(name=user_data[’name’], gender=user_data[’gender’]) ok = True return CreateUser(user=user, ok=ok)# 定義一個創建博客的mutationclass CreateBlog(graphene.Mutation): class Arguments: blog_data = BlogInput(required=True) blog = graphene.Field(BlogType) def mutate(self, info, blog_data): # 插入到數據庫中 blog = Blog.objects.create(title=blog_data[’title’], user_id=blog_data[’user’], content=blog_data[’content’]) return CreateBlog(blog=blog)# 定義一個查詢語句class Query(object): all_user = graphene.List(UserType) all_blog = graphene.List(BlogType) def resolve_all_user(self, info, **kwargs): # 查詢所有book的邏輯 return User.objects.all() def resolve_all_blog(self, info, **kwargs): # 查詢所有title的邏輯 return Blog.objects.all()

3、在跟目錄(和settings.py同級)創建一個項目的總schema.py

import grapheneimport book.schema, blog.schemaclass Query(blog.schema.Query, graphene.ObjectType): # 總的Schema的query入口 passclass Mutations(graphene.ObjectType): # 總的Schema的mutations入口 create_user = blog.schema.CreateUser.Field() create_blog = blog.schema.CreateBlog.Field()schema = graphene.Schema(query=Query, mutation=Mutations)

4、配置url地址

from django.contrib import adminfrom django.urls import pathfrom graphene_django.views import GraphQLViewfrom .schema import schemaurlpatterns = [ path(’admin/’, admin.site.urls), path(’graphql/’, GraphQLView.as_view(graphiql=True, schema=schema)),]

5、生成數據庫映射及啟動項目,直接在瀏覽器上訪問

四、可以對上面的代碼調整

1、把Mutations也單獨定義在各自的schema.py中

# 定義一個總的mutation出口class Mutation(graphene.AbstractType): create_user = CreateUser.Field() create_blog = CreateBlog.Field()

2、在總的schema.py中引入類型Query一樣的操作

class Mutations(blog.schema.Mutation, graphene.ObjectType): # 總的Schema的mutations入口 pass

3、輸入數據類型可以直接定義在mutation里面

class CreateUser(graphene.Mutation): # api的輸入參數(類名可以隨便定義) class Arguments: name = graphene.String(required=True) gender = graphene.String(required=True) # api的響應參數 ok = graphene.Boolean() user = graphene.Field(UserType) # api的相應操作，這里是create def mutate(self, info, name, gender): user = User.objects.create(name=name, gender=gender) ok = True return CreateUser(user=user, ok=ok)

五、Query語句中使用條件查詢

1、app的schema(官方案例)

import graphenefrom graphene_django.types import DjangoObjectTypefrom .models import Category, Ingredientclass CategoryType(DjangoObjectType): class Meta: model = Categoryclass IngredientType(DjangoObjectType): class Meta: model = Ingredient# 定義一個查詢class Query(object): # 定義一個根據id或者name查詢的 category = graphene.Field(CategoryType,id=graphene.Int(),name=graphene.String()) # 查詢全部的 all_categories = graphene.List(CategoryType) # 根據條件查詢 ingredient = graphene.Field(IngredientType,id=graphene.Int(),name=graphene.String()) # 查詢全部的 all_ingredients = graphene.List(IngredientType) def resolve_all_categories(self, info, **kwargs): return Category.objects.all() def resolve_all_ingredients(self, info, **kwargs): # We can easily optimize query count in the resolve method return Ingredient.objects.select_related(’category’).all() # 定義查詢語句 def resolve_category(self, info, **kwargs): id = kwargs.get(’id’) name = kwargs.get(’name’) if id is not None: return Category.objects.get(pk=id) if name is not None: return Category.objects.get(name=name) return None def resolve_ingredient(self, info, **kwargs): id = kwargs.get(’id’) name = kwargs.get(’name’) if id is not None: return Ingredient.objects.get(pk=id) if name is not None: return Ingredient.objects.get(name=name) return None

官網地址

補充知識：記錄下python中使用定時器的幾種方法

方式一、直接使用while循環的方式

from datetime import datetimeimport time# 每n秒執行一次def timer(n): while True: print(datetime.now().strftime('%Y-%m-%d %H:%M:%S')) time.sleep(n)timer(5)

方式二、使用threading模塊中的Timer

from datetime import datetimefrom threading import Timer# 打印時間函數def print_time(inc): print(datetime.now().strftime('%Y-%m-%d %H:%M:%S')) ''' Timer的參數說明 inc:表示時間間隔 print_time:執行的函數 (inc,):傳遞給執行函數的參數 ''' t = Timer(inc, print_time, (inc,)) t.start()print_time(2)

方式三、使用sched模塊

import timeimport schedfrom datetime import datetime# 初始化 sched 模塊的 scheduler 類# 第一個參數是一個可以返回時間戳的函數，第二個參數可以在定時未到達之前阻塞。schedule = sched.scheduler(time.time, time.sleep)# 被周期性調度觸發的函數def print_time(inc): print(datetime.now().strftime('%Y-%m-%d %H:%M:%S')) schedule.enter(inc, 0, print_time, (inc,))# 默認參數 60 sdef start(inc=60): # enter四個參數分別為：間隔事件、優先級（用于同時間到達的兩個事件同時執行時定序）、被調用觸發的函數、給觸發函數的參數（tuple形式） schedule.enter(0, 0, print_time, (inc,)) schedule.run()if __name__ == '__main__': start(10)

方式四、使用apscheduler

from apscheduler.schedulers.blocking import BlockingSchedulerfrom datetime import datetimedef job(): print(datetime.now().strftime(’%Y-%m-%d %H:%M:%S’))if __name__ == '__main__': scheduler = BlockingScheduler() scheduler.add_job(job, ’interval’, seconds=5) scheduler.start()

以上這篇django使用graphql的實例就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持好吧啦網。