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django使用graphql

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一、開發環境

  • 1、

    python3.6

  • 2、

    django2.0

  • 3、

    window10

二、項目搭建

  • 1、建立一個虛拟空間

    mkvirtualenv 空間名

  • 2、建立一個

    django

    項目
  • 3、安裝

    graphql

    的依賴包
    pip install graphene-django
               
  • 4、建立一個元件

    blog

  • 5、把元件

    blog

    graphene_django

    注入到

    app

  • 6、在

    settings.py

    中配置

    mysql

    資料庫連接配接

三、書寫

blog

的内容

  • 1、在

    models.py

    中寫上資料模型
    from django.db import models
    
    
    # Create your models here.
    class User(models.Model):
        name = models.CharField(max_length=100, verbose_name="部落客名字")
        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='建立時間')
    
    
    class Blog(models.Model):
        title = models.CharField(max_length=100, verbose_name='标題')
        user = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL, verbose_name='部落客名字')
        content = models.TextField(verbose_name='部落格内容')
        create_at = models.DateTimeField(auto_now_add=True, verbose_name='建立時間')
        update_at = models.DateTimeField(auto_now=True, verbose_name='更新時間')
               
  • 2、建立一個

    schema.py

    檔案
    #!/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)
    
    
    # 定義一個建立user的mutation
    class 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,這裡是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)
    
    
    # 定義一個建立部落格的mutation
    class CreateBlog(graphene.Mutation):
        class Arguments:
            blog_data = BlogInput(required=True)
    
        blog = graphene.Field(BlogType)
    
        def mutate(self, info, blog_data):
            # 插入到資料庫中
            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)建立一個項目的總

    schema.py

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

    位址
    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、生成資料庫映射及啟動項目,直接在浏覽器上通路

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

    # 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、輸入資料類型可以直接定義在

    mutation

    裡面
    class CreateUser(graphene.Mutation):
        # api的輸入參數(類名可以随便定義)
        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,這裡是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

    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
               

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