Question

我的系统上有3个模型

Public class Company {Id,Name}//Already have data

Public Class User {Id, Name}//Already have data

Public Class Department {Id,Name,CompanyId,UserId,Public Company Companies,Public User Users}

现在我想为我的部门模型创建种子数据。我的种子数据类中的代码；

if(!context.Department.Any()){

try {
var departments = new Department[]{
 new Department{ComapnyId=context.Companies.Single(s => s.Name=="Stackoverflow").Id,
     UserId =context.Users.Single(s => s.Name=="Admin").Id, Name="IT"}
};
  foreach (Department department in departments)
                        {
                            context.Department.Add(department);                         
                        }
                        context.SaveChanges();
}catch (Exception e)
            {
                throw new Exception(e.Message);
            }//End Try and Catch
}//End If

现在，我的问题保存方法总是删除异常。

我在做什么错？？

我的Stacktrace：at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action 1 wrapCloseInAction）在System.Data.SqlClient.SqlInternalConnection.OnError（SqlException异常，布尔breakConnection，Action 1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, TaskCompletionSource 1完成，Int32超时，任务和任务，布尔asyncWrite，String方法）在System.Data.SqlClient.SqlCommand.ExecuteReader（CommandBehavior行为）在System.Data.SqlClient.SqlCommand.ExecuteDbDataReader（CommandBehavior行为）在System.Data.Common.DbCommand.ExecuteReader（）在Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute（IRelationalConnection连接，DbCommandMethod executeMethod，IReadOnlyDictionary 2 parameterValues) at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteReader(IRelationalConnection connection, IReadOnlyDictionary 2参数值）处在Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.Execute（IRelationalConnection连接） ---内部异常堆栈跟踪的结尾---`

Answer 1

您需要按照以下说明正确配置模型之间的关联；

每个用户将拥有一个公司和一个部门
每个部门将拥有一个公司和多个用户
每个公司都会有许多用户和许多部门

因此，您的数据模型必须如下所示：

select distinct on (subject_id) subject_id, hadm_id
from labevents
where itemid in ('50809','50931','51529') 
  AND valuenum > 110 
  and hadm_id is not null
order by subject_id, row_id;

稍后我们可以看到您面临的错误。

为什么我的保存方法总是给出异常而不保存值

1 个答案: