EF Core SQLite 错误 19：尽管配置了一对多，但“外键约束失败”

Question

我查看了文档和其他几个答案，但找不到我的问题所在。我与Student 和ReportCard 有一对多的关系，就像这样

public class Student
{
    public long StudentId { get; set; }
    public string Name { get; set; }
    public Grade CurrentGradeLevel { get; set; }

    public ICollection<Guardian> Guardians { get; set; }
    public ICollection<Result> Results { get; set; }
    public ICollection<ReportCard> ReportCards { get; set; }
}

public class ReportCard
{
    public long ReportCardId { get; set; }
    public long StudentId { get; set; }
    public double OverallGrade { get; set;}

    public Student Student { get; set; }
    public Grade GradeLevel { get; set; }

    public ICollection<CourseGrade> Grades { get; set; }
}

我在StudentContext 中配置了这样的关系：

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Student>()
                .HasMany(s => s.ReportCards)
                .WithOne(r => r.Student)
                .OnDelete(DeleteBehavior.Cascade);
}

然而，当我尝试删除 ReportCard 时，会发生此错误

Microsoft.EntityFrameworkCore.Database.Command[20102]
      Failed executing DbCommand (1ms) [Parameters=[@p0='?'], CommandType='Text', CommandTimeout='30']
      DELETE FROM "ReportCards"
      WHERE "ReportCardId" = @p0;
      SELECT changes();
fail: Microsoft.EntityFrameworkCore.Update[10000]
      An exception occurred in the database while saving changes for context type 'Onero.Server.Models.ReportCardContext'.
      Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details.
       ---> Microsoft.Data.Sqlite.SqliteException (0x80004005): SQLite Error 19: 'FOREIGN KEY constraint failed'.
         at Microsoft.Data.Sqlite.SqliteException.ThrowExceptionForRC(Int32 rc, sqlite3 db)
         at Microsoft.Data.Sqlite.SqliteDataReader.NextResult()
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReader(CommandBehavior behavior)
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteDbDataReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
         --- End of inner exception stack trace ---
         at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(DbContext _, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
      Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details.
       ---> Microsoft.Data.Sqlite.SqliteException (0x80004005): SQLite Error 19: 'FOREIGN KEY constraint failed'.
         at Microsoft.Data.Sqlite.SqliteException.ThrowExceptionForRC(Int32 rc, sqlite3 db)
         at Microsoft.Data.Sqlite.SqliteDataReader.NextResult()
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReader(CommandBehavior behavior)
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteDbDataReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
         --- End of inner exception stack trace ---
         at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(DbContext _, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
fail: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware[1]
      An unhandled exception has occurred while executing the request.
      Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details.
       ---> Microsoft.Data.Sqlite.SqliteException (0x80004005): SQLite Error 19: 'FOREIGN KEY constraint failed'.
         at Microsoft.Data.Sqlite.SqliteException.ThrowExceptionForRC(Int32 rc, sqlite3 db)
         at Microsoft.Data.Sqlite.SqliteDataReader.NextResult()
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReader(CommandBehavior behavior)
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
         at Microsoft.Data.Sqlite.SqliteCommand.ExecuteDbDataReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
         --- End of inner exception stack trace ---
         at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(DbContext _, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
         at Onero.Server.Controllers.ReportCardController.DeleteReportCard(Int64 id) in /home/adrian/workspace/Onero/Server/Controllers/ReportCardController.cs:line 106
         at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
      --- End of stack trace from previous location ---
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
      --- End of stack trace from previous location ---
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
         at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
         at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
         at IdentityServer4.Hosting.IdentityServerMiddleware.Invoke(HttpContext context, IEndpointRouter router, IUserSession session, IEventService events, IBackChannelLogoutService backChannelLogoutService)
         at IdentityServer4.Hosting.MutualTlsEndpointMiddleware.Invoke(HttpContext context, IAuthenticationSchemeProvider schemes)
         at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
         at IdentityServer4.Hosting.BaseUrlMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.MigrationsEndPointMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
fail: Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseDeveloperPageExceptionFilter[7]
      An exception occurred while calculating the database error page content. Skipping display of the database error page.
      System.InvalidOperationException: StatusCode cannot be set because the response has already started.
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ThrowResponseAlreadyStartedException(String value)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.set_StatusCode(Int32 value)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.Microsoft.AspNetCore.Http.Features.IHttpResponseFeature.set_StatusCode(Int32 value)
         at Microsoft.AspNetCore.Http.DefaultHttpResponse.set_StatusCode(Int32 value)
         at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.Views.DatabaseErrorPage.ExecuteAsync()
         at Microsoft.Extensions.RazorViews.BaseView.ExecuteAsync(HttpContext context)
         at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseDeveloperPageExceptionFilter.HandleExceptionAsync(ErrorContext errorContext, Fun

为什么会这样？感谢您的帮助。

编辑

根据要求，这里是CourseGrade

    public class CourseGrade
    {
        public long CourseGradeId { get; set; }
        public long CourseModelId { get; set; }
        public long StudentId { get; set; }
        public double Grade { get; set; }
    }

这是我刚刚用邮递员调用的删除 api

        [HttpDelete("{id}")]
        public async Task<IActionResult> DeleteReportCard(long id)
        {
            var reportCard = await _context.ReportCards.FindAsync(id);
            if (reportCard == null)
            {
                return NotFound();
            }

            _context.ReportCards.Remove(reportCard);
            await _context.SaveChangesAsync();

            return NoContent();
        }

第二次编辑：包含整个错误消息。

Answer 1

您在 CourseGrade 课程中有一个错误

public ICollection<CourseGrade> Grades { get; set; }

你不能这样使用它，因为你没有 ReportCardId，EF 核心必须添加 ReportCardId 作为 CourseGrade 的影子属性。这就是导致错误的原因。您必须首先从 CourseGrade 中删除带有 ReportCardId 的记录。或者如果您不需要它，请删除属性 Grades 并再次进行 db 迁移