我有.Net Core web API可以正常工作。当我尝试添加实体框架核心时,首先是编译错误。它说,即使我使用了.Net Core 3.1,我也必须添加Microsoft.Bcl.AsyncInterfaces。当我添加这个时,编译得很好,但当api运行时,它会出现这个异常。我在互联网上找不到这个例外的任何解决方案:
运行.net核心web api(调试(时:
namespace CoreWebApi{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.AddDbContext<PKDbContext>(options =>
options.UseMySql(Configuration.GetConnectionString("LocalConnection")));
services.AddScoped(typeof(IBankProduct), typeof(BankProductRepo));
services.AddScoped(typeof(IProductType), typeof(ProductTypeRepo));
services.AddScoped(typeof(IProductRequest), typeof(ProductRequestRepo));
services.AddScoped(typeof(IProfile), typeof(ProfileRepo));
services.AddScoped(typeof(INotification), typeof(NotificationRepo));
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
}
启动代码工作正常。当我的dbContext类(PKDbContext(运行时,它在这一部分给出异常:(:base(options((
public class PKDbContext : DbContext{
public PKDbContext() { }
public PKDbContext(DbContextOptions<PKDbContext> options) : base(options)
{
// some codes
}
}
引发异常:Microsoft.EntityFrameworkCore.dll中的"System.InvalidOperationException"Microsoft.EntityFrameworkCore.dll中出现类型为"System.InvalidOperationException"的异常,但未在用户代码中进行处理数据库提供程序试图注册"IRelationTypeMappingSource"服务的实现。这不是EF定义的服务,因此必须使用"TryAddProviderSpecificServices"方法注册为特定于提供程序的服务。
*编辑:我正在使用Pomelo.EntityFrameworkCore.MySql
**编辑:我添加了csproj文件代码:
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp3.1</TargetFramework>
<StartupObject>CoreWebApi.Program</StartupObject>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="1.1.1" />
<PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.0-preview.7.20365.15" />
<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="5.0.0-preview.7.20365.15" />
<PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="3.1.2" />
</ItemGroup>
</Project>
有同样的问题,原来Pomelo.EntityFrameworkCore.MySql的当前版本需要3.1.8到5.0.0 之前的Microsoft.EntityFrameworkCore版本
将Microsoft.EntityFrameworkCore降级到5.0.0(3.1.11(之前的版本为我解决了问题
我决定将数据库更改为Sql Server。我已经删除了Pomelo.EntityFrameworkCore.MySql,并添加了Microsoft.EntityFrameworkCore.SqlServer,问题已经解决。
如果您希望EF Core 5
与MySQL一起使用,则需要安装Pomelo.EntityFrameworkCore.MySql 5.0.0-alpha.2
<PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.3" />
<PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="5.0.0-alpha.2" />
或者您可以将Pomelo.EntityFrameworkCore.MySql
降级到更稳定的版本,即3.2.4
和EF Core 3.1.12
<PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.12" />
<PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="3.2.4" />
PS:欲了解更多信息,请访问Pomelo.EntityFrameworkCore.MySql
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