一、开发环境
1、python3.6
2、django2.0
3、window10
二、项目搭建
1、创建一个虚拟空间mkvirtualenv 空间名
2、创建一个django项目
3、安装graphql的依赖包
pip install graphene-django
4、创建一个组件blog
5、把组件blog及graphene_django注入到app中
6、在settings.py中配置mysql数据库连接
三、书写blog的内容
1、在models.py中写上数据模型
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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='性别') create_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')class Blog(models.Model): title = models.CharField(max_length=100, verbose_name='标题') user = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL, verbose_name='博主名字') content = models.TextField(verbose_name='博客内容') create_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间') update_at = models.DateTimeField(auto_now=True, verbose_name='更新时间') |
2、新建一个schema.py文件
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#!/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# 定义动作约素输入类型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)# 定义一个创建user的mutationclass CreateUser(graphene.Mutation): # api的输入参数 class Arguments: user_data = UserInput(required=True) # api的响应参数 ok = graphene.Boolean() user = graphene.Field(UserType) # api的相应操作，这里是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)# 定义一个创建博客的mutationclass CreateBlog(graphene.Mutation): class Arguments: blog_data = BlogInput(required=True) blog = graphene.Field(BlogType) def mutate(self, info, blog_data): # 插入到数据库中 blog = Blog.objects.create(title=blog_data['title'], user_id=blog_data['user'], content=blog_data['content']) return CreateBlog(blog=blog)# 定义一个查询语句class Query(object): all_user = graphene.List(UserType) all_blog = graphene.List(BlogType) def resolve_all_user(self, info, **kwargs): # 查询所有book的逻辑 return User.objects.all() def resolve_all_blog(self, info, **kwargs): # 查询所有title的逻辑 return Blog.objects.all() |
3、在跟目录(和settings.py同级)创建一个项目的总schema.py
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import grapheneimport book.schema, blog.schemaclass Query(blog.schema.Query, graphene.ObjectType): # 总的Schema的query入口 passclass Mutations(graphene.ObjectType): # 总的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
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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、生成数据库映射及启动项目,直接在浏览器上访问
四、可以对上面的代码调整
1、把Mutations也单独定义在各自的schema.py中
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# 定义一个总的mutation出口class Mutation(graphene.AbstractType): create_user = CreateUser.Field() create_blog = CreateBlog.Field() |
2、在总的schema.py中引入类型Query一样的操作
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class Mutations(blog.schema.Mutation, graphene.ObjectType): # 总的Schema的mutations入口 pass |
3、输入数据类型可以直接定义在mutation里面
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class CreateUser(graphene.Mutation): # api的输入参数(类名可以随便定义) class Arguments: name = graphene.String(required=True) gender = graphene.String(required=True) # api的响应参数 ok = graphene.Boolean() user = graphene.Field(UserType) # api的相应操作，这里是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语句中使用条件查询
1、app的schema(官方案例)
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import graphenefrom graphene_django.types import DjangoObjectTypefrom .models import Category, Ingredientclass CategoryType(DjangoObjectType): class Meta: model = Categoryclass IngredientType(DjangoObjectType): class Meta: model = Ingredient# 定义一个查询class Query(object): # 定义一个根据id或者name查询的 category = graphene.Field(CategoryType, id=graphene.Int(), name=graphene.String()) # 查询全部的 all_categories = graphene.List(CategoryType) # 根据条件查询 ingredient = graphene.Field(IngredientType, id=graphene.Int(), name=graphene.String()) # 查询全部的 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() # 定义查询语句 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 |
补充知识：记录下python中使用定时器的几种方法
方式一、直接使用while循环的方式
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from datetime import datetimeimport time# 每n秒执行一次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模块中的Timer
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from datetime import datetimefrom threading import Timer# 打印时间函数def print_time(inc): print(datetime.now().strftime("%Y-%m-%d %H:%M:%S")) """ Timer的参数说明 inc:表示时间间隔 print_time:执行的函数 (inc,):传递给执行函数的参数 """ t = Timer(inc, print_time, (inc,)) t.start()print_time(2) |
方式三、使用sched模块
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import timeimport schedfrom datetime import datetime# 初始化 sched 模块的 scheduler 类# 第一个参数是一个可以返回时间戳的函数，第二个参数可以在定时未到达之前阻塞。schedule = sched.scheduler(time.time, time.sleep)# 被周期性调度触发的函数def print_time(inc): print(datetime.now().strftime("%Y-%m-%d %H:%M:%S")) schedule.enter(inc, 0, print_time, (inc,))# 默认参数 60 sdef start(inc=60): # enter四个参数分别为：间隔事件、优先级（用于同时间到达的两个事件同时执行时定序）、被调用触发的函数、给触发函数的参数（tuple形式） schedule.enter(0, 0, print_time, (inc,)) schedule.run()if __name__ == "__main__": start(10) |
方式四、使用apscheduler
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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() |
以上这篇django使用graphql的实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/kuangshp128/article/details/79370351
