django使用graphql

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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

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


#!/usr/bin/env python


# encoding: utf-8


import graphene
from graphene_django.types import DjangoObjectType
from .models import User, Blog


class UserType(DjangoObjectType):
    class Meta:
        model = User


class 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mutation

class 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mutation

class 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

import graphene
import book.schema, blog.schema


class Query(blog.schema.Query, graphene.ObjectType):
    # 总的Schema的query入口
    pass


class 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

from django.contrib import admin
from django.urls import path
from graphene_django.views import GraphQLView
from .schema import schema
urlpatterns = [
    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


# 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

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

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)

import graphene
from graphene_django.types import DjangoObjectType
from .models import Category, Ingredient


class CategoryType(DjangoObjectType):
    class Meta:
        model = Category


class 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

一、开发环境

二、项目搭建

三、书写blog的内容

四、可以对上面的代码调整

五、Query语句中使用条件查询

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三、书写`blog`的内容

五、`Query`语句中使用条件查询