Question

在EF Core中，我有两个彼此具有1-1关系的模型。

MultiPlayerPlay：

public class MultiPlayerPlay
{
    public long Id { get; set; }
    ...

    // Relations
    ...
    public long? CallerPlayerPlayId { get; set; }
    public virtual UserMutantPlay CallerPlayerPlay { get; set; }
    public long? CalledPlayerPlayId { get; set; }
    public virtual UserMutantPlay CalledPlayerPlay { get; set; }
    ...
}

和UserMutantPlay：

public class UserMutantPlay
{
    public long Id { get; set; }
    ...

    // Relations
    ...
    public long? MultiPlayerPlayAsCallerId { get; set; }
    public virtual MultiPlayerPlay MultiPlayerPlayAsCaller { get; set; }
    public long? MultiPlayerPlayAsCalledId { get; set; }
    public virtual MultiPlayerPlay MultiPlayerPlayAsCalled { get; set; }
}

和关系：

        modelBuilder.Entity<MultiPlayerPlay>()
            .HasOne(mpp => mpp.CallerPlayerPlay)
            .WithOne(p => p.MultiPlayerPlayAsCaller)
            .HasForeignKey<MultiPlayerPlay>(mpp => mpp.CallerPlayerPlayId)
            //.HasForeignKey<UserMutantPlay>(ump => ump.MultiPlayerPlayAsCallerId)
            .IsRequired(false)
            .OnDelete(Microsoft.EntityFrameworkCore.Metadata.DeleteBehavior.Restrict);

        modelBuilder.Entity<MultiPlayerPlay>()
            .HasOne(mpp => mpp.CalledPlayerPlay)
            .WithOne(p => p.MultiPlayerPlayAsCalled)
            .HasForeignKey<MultiPlayerPlay>(mpp => mpp.CalledPlayerPlayId)
            //.HasForeignKey<UserMutantPlay>(ump => ump.MultiPlayerPlayAsCalledId)
            .IsRequired(false)
            .OnDelete(Microsoft.EntityFrameworkCore.Metadata.DeleteBehavior.Restrict);

如您所见，MultiPlayerPlay与UserMutantPlay有两个1-1关系。但是当我试图运行这个陈述时：

    MultiPlayerPlay multiPlayerPlay = new MultiPlayerPlay()
        {
            CallerPlayerId = inviterUser.Id,
            CalledPlayerId = invitedUser.Id,
            StillRunning = true,
            StillRunningForCaller = true,
            StillRunningForCalled = true,
            MutantId = GetRandomMutantIdByLevelId(dbContext, inviterUser.Id, invitedUser.Id),
        };

        dbContext.MultiPlayerPlays.Add(multiPlayerPlay);
        dbContext.SaveChanges();

第一次它工作正常。接下来，它提到我在FK关系中不能有多个空值。错误是这样的：

{System.Data.SqlClient.SqlException：无法在对象＆＃39; dbo.MultiPlayerPlays＆＃39;中插入重复的键行。具有唯一索引＆＃39; IX_MultiPlayerPlays_CalledPlayerPlayId＆＃39;。重复键值为（）。该语句已终止。在System.Data.SqlClient.SqlConnection.OnError（SqlException异常，Boolean 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.ExecuteReader(CommandBehavior behavior) at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(IRelationalConnection connection, String executeMethod, IReadOnlyDictionary 2 parameterValues，Boolean closeConnection）在Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteReader（IRelationalConnection连接，IReadOnlyDictionary`2 parameterValues）在Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.Execute（IRelationalConnection连接） ClientConnectionId：7c7adc7b-0172-4134-89c9-6b5f050ac860 错误号码：2601，州：1，班级：14}

EF Core可以为空的一对一关系不允许重复空值

0 个答案: