今天给大家分享.NET中的GraphQL，半个小时，没有把所有的代码敲出来，高估了自己的写码速度，所以通过这个文章分享出来。

1、核心PPT

2、主要代码

using Conf2021GraphQL;
using Conf2021GraphQL.Models;
using Microsoft.EntityFrameworkCore;
using System.Security.Cryptography;var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder.Services.AddDbContext<ExamContext>(options =>options.UseSqlServer(builder.Configuration.GetConnectionString("ExamDatabase")));builder.Services.AddGraphQLServer().AddQueryType<Query>().AddTypeExtension<ExtendExamPaper>().AddInterfaceType<IDescribe>().AddType<SubjectTypeDescribe>().AddType<QuestionTypeDescribe>().AddMutationType<UserMutation>().AddProjections().AddFiltering().AddSorting();var app = builder.Build();
if (app.Environment.IsDevelopment())
{app.UseSwagger();app.UseSwaggerUI();
}
app.UseAuthorization();
app.MapControllers();app.MapGraphQL();app.Run();public class Query
{[Serial][UseProjection][UseFiltering][UseSorting]public IQueryable<ExamPaper> GetExamPapers([Service] ExamContext context) => context.ExamPapers;[Serial][UseProjection][UseFiltering][UseSorting]public IQueryable<User> GetUsers([Service] ExamContext context) => context.Users;[UseProjection][UseFiltering][UseSorting]public IQueryable<IDescribe> GetDescribes(){return new List<IDescribe>{new SubjectTypeDescribe{Describe ="问题科目类型"},new QuestionTypeDescribe{Describe ="试题类型 "},}.AsQueryable();}
}[ExtendObjectType(typeof(ExamPaper))]
public class ExtendExamPaper
{public int Count([Parent] ExamPaper paper) => paper.Questions.Count;
}public interface IDescribe
{string? Describe { get; set; }
}
public class SubjectTypeDescribe : IDescribe
{public string? Describe { get; set; }
}
public class QuestionTypeDescribe : IDescribe
{public string? Describe { get; set; }public string[] Types { get; set; } = new string[] { "单选题", "多选题", "判断题" };
}public class UserMutation
{public async Task<User> AddUser(User user, [Service] ExamContext context, CancellationToken cancellationToken){var password = GetRandomString(8);user.Password = System.Text.Encoding.UTF8.GetString(SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(password + user.Salt)));await context.Users.AddAsync(user);await context.SaveChangesAsync(cancellationToken);user.Password = password;return user;}string GetRandomString(int length){string result = "";for (int i = 0; i < length; i++){char c = (char)new Random(Guid.NewGuid().GetHashCode()).Next(48, 123);result += c;}return result;}
}

3、GraphQL查询

查询，过滤，排序，扩展

继承

mutation

mutation结果查询

4、githtub库：

https://github.com/axzxs2001/Conf2021GraphQL

5、数据库结构

USE [Exam]
GO
/****** Object:  Table [dbo].[Answers]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Answers]([ID] [int] IDENTITY(1,1) NOT NULL,[Sequre] [nvarchar](8) NOT NULL,[Answer] [nvarchar](200) NOT NULL,[IsTrue] [bit] NOT NULL,[QuestionID] [int] NOT NULL,CONSTRAINT [PK_Answers] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[ExamPaperQuestions]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[ExamPaperQuestions]([ExamPaperID] [int] NOT NULL,[QuestionID] [int] NOT NULL,CONSTRAINT [PK_ExamPaperQuestions_1] PRIMARY KEY CLUSTERED
([ExamPaperID] ASC,[QuestionID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[ExamPapers]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[ExamPapers]([ID] [int] IDENTITY(1,1) NOT NULL,[Title] [nvarchar](200) NOT NULL,[Memo] [nvarchar](1000) NULL,[CreateTime] [datetime2](7) NOT NULL,CONSTRAINT [PK_ExamPapers] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[Questions]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Questions]([ID] [int] IDENTITY(1,1) NOT NULL,[Question] [nvarchar](300) NOT NULL,[Score] [float] NOT NULL,[QuestionTypeID] [int] NOT NULL,[SujectTypeID] [int] NOT NULL,CONSTRAINT [PK_Questions] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[QuestionTypes]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[QuestionTypes]([ID] [int] IDENTITY(1,1) NOT NULL,[TypeName] [nvarchar](50) NOT NULL,CONSTRAINT [PK_QuestionTypes] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[SubjectTypes]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[SubjectTypes]([ID] [int] IDENTITY(1,1) NOT NULL,[TypeName] [nvarchar](50) NOT NULL,CONSTRAINT [PK_SubjectTypes] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[UserExamAnswers]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[UserExamAnswers]([ID] [int] IDENTITY(1,1) NOT NULL,[UserExamID] [int] NOT NULL,[AnswerID] [int] NOT NULL,[CreateTime] [datetime] NOT NULL,CONSTRAINT [PK_UserExamAnswers] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[UserExams]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[UserExams]([ID] [int] IDENTITY(1,1) NOT NULL,[UserID] [int] NOT NULL,[ExamPapgerID] [int] NOT NULL,[BeginTime] [datetime] NOT NULL,[EndTime] [datetime] NOT NULL,CONSTRAINT [PK_UserExams] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[Users]    Script Date: 2021/12/18 23:36:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Users]([ID] [int] IDENTITY(1,1) NOT NULL,[UserName] [nvarchar](50) NOT NULL,[Password] [nvarchar](50) NOT NULL,[Salt] [nvarchar](50) NOT NULL,[Name] [nvarchar](50) NOT NULL,[Tel] [varchar](11) NULL,CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED
([ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[ExamPapers] ADD  DEFAULT (getdate()) FOR [CreateTime]
GO
ALTER TABLE [dbo].[UserExamAnswers] ADD  DEFAULT (getdate()) FOR [CreateTime]
GO
ALTER TABLE [dbo].[Answers]  WITH CHECK ADD  CONSTRAINT [FK_Answers_Questions] FOREIGN KEY([QuestionID])
REFERENCES [dbo].[Questions] ([ID])
GO
ALTER TABLE [dbo].[Answers] CHECK CONSTRAINT [FK_Answers_Questions]
GO
ALTER TABLE [dbo].[ExamPaperQuestions]  WITH CHECK ADD  CONSTRAINT [FK_ExamPaperQuestions_ExamPapers] FOREIGN KEY([ExamPaperID])
REFERENCES [dbo].[ExamPapers] ([ID])
GO
ALTER TABLE [dbo].[ExamPaperQuestions] CHECK CONSTRAINT [FK_ExamPaperQuestions_ExamPapers]
GO
ALTER TABLE [dbo].[ExamPaperQuestions]  WITH CHECK ADD  CONSTRAINT [FK_ExamPaperQuestions_Questions] FOREIGN KEY([QuestionID])
REFERENCES [dbo].[Questions] ([ID])
GO
ALTER TABLE [dbo].[ExamPaperQuestions] CHECK CONSTRAINT [FK_ExamPaperQuestions_Questions]
GO
ALTER TABLE [dbo].[Questions]  WITH CHECK ADD  CONSTRAINT [FK_Questions_QuestionTypes] FOREIGN KEY([QuestionTypeID])
REFERENCES [dbo].[QuestionTypes] ([ID])
GO
ALTER TABLE [dbo].[Questions] CHECK CONSTRAINT [FK_Questions_QuestionTypes]
GO
ALTER TABLE [dbo].[Questions]  WITH CHECK ADD  CONSTRAINT [FK_Questions_SubjectTypes] FOREIGN KEY([SujectTypeID])
REFERENCES [dbo].[SubjectTypes] ([ID])
GO
ALTER TABLE [dbo].[Questions] CHECK CONSTRAINT [FK_Questions_SubjectTypes]
GO
ALTER TABLE [dbo].[UserExamAnswers]  WITH CHECK ADD  CONSTRAINT [FK_UserExamAnswers_Answers] FOREIGN KEY([AnswerID])
REFERENCES [dbo].[Answers] ([ID])
GO
ALTER TABLE [dbo].[UserExamAnswers] CHECK CONSTRAINT [FK_UserExamAnswers_Answers]
GO
ALTER TABLE [dbo].[UserExamAnswers]  WITH CHECK ADD  CONSTRAINT [FK_UserExamAnswers_UserExams] FOREIGN KEY([UserExamID])
REFERENCES [dbo].[UserExams] ([ID])
GO
ALTER TABLE [dbo].[UserExamAnswers] CHECK CONSTRAINT [FK_UserExamAnswers_UserExams]
GO
ALTER TABLE [dbo].[UserExams]  WITH CHECK ADD  CONSTRAINT [FK_UserExams_ExamPapers] FOREIGN KEY([ExamPapgerID])
REFERENCES [dbo].[ExamPapers] ([ID])
GO
ALTER TABLE [dbo].[UserExams] CHECK CONSTRAINT [FK_UserExams_ExamPapers]
GO
ALTER TABLE [dbo].[UserExams]  WITH CHECK ADD  CONSTRAINT [FK_UserExams_Users] FOREIGN KEY([UserID])
REFERENCES [dbo].[Users] ([ID])
GO
ALTER TABLE [dbo].[UserExams] CHECK CONSTRAINT [FK_UserExams_Users]
GO