.net core 3.1 使用EntityFrameworkcore

首先安装 EntityFrameworkcore 注意版本5.0.0的不兼容

必须装用于运行命令，同样注意版本

使用最新版就好

使用最新版就好

 

这里可以运行命令

执行命令

Scaffold-DbContext "server=192.168.1.1;port=3306;user=test;password=123456;database=cloud;" Pomelo.EntityFrameworkCore.MySql -OutputDir Models -Force

执行后结果查看 

需要在startup中注册

在项目中建立如下文件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using WLCloudAPI.Models;

namespace WLCloudAPI.Repositories
{
    public interface ITestRepository
    {
        Task<IEnumerable<Test>> GetTestAsync();
        Task<IEnumerable<Test>> GetTest();
        Task<Test> GetTestAsync(int companyId);
        void AddTest(Test company);
        Task<bool> SaveAsync();
    }
}

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using WLCloudAPI.Models;

namespace WLCloudAPI.Repositories
{
    class TestRepository : ITestRepository
    {
        private readonly wlcloudContext _myDbContext;

        public TestRepository(wlcloudContext myDbContext)
        {
            _myDbContext = myDbContext ?? throw new ArgumentNullException(nameof(myDbContext));
        }
        public async Task<IEnumerable<Test>> GetTestAsync()
        {
            return await _myDbContext.Test.ToArrayAsync();
        }

        public async Task<IEnumerable<Test>> GetTest()
        {
            return await _myDbContext.Test.ToListAsync();
        }

        public async Task<Test> GetTestAsync(int companyId)
        {
            return await _myDbContext.Test.FirstOrDefaultAsync(x => x.Id == companyId);
        }

        public void AddTest(Test company)
        {
            _myDbContext.Test.Add(company);
        }

        public async Task<bool> SaveAsync()
        {
            return await _myDbContext.SaveChangesAsync() >= 0;
        }
    }
}

 在webapi中的controller中使用

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.Json.Serialization;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using WLCloudAPI.Models;
using WLCloudAPI.Repositories;
using WLCloudAPI.util;

namespace WLCloudAPI.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class testController : Controller
    {
        private readonly ITestRepository _testRepository;

        // 注入testRepository，就可以直接在控制器中使用其方法了
        public testController(ITestRepository testRepository)
        {
            _testRepository = testRepository;
        }

        [HttpGet]
        public async Task<IEnumerable<Test>> Get1()
        {
          return await _testRepository.GetTest();

        }

    }

配置文件读取类 

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WLCloudAPI.util
{
    public class AppSettingsHelper
    {
        public static IConfiguration Configuration { get; set; }
        static AppSettingsHelper()
        {
            //ReloadOnChange = true 当appsettings.json被修改时重新加载            
            Configuration = new ConfigurationBuilder()
            .Add(new JsonConfigurationSource { Path = "appsettings.json", ReloadOnChange = true })
            .Build();
        }

    }

}