所以我有这张表：

CREATE TABLE [Snapshots].[Crashproof](
    [EmoteCountId] [int] IDENTITY(1,1) NOT NULL,
    [SnapshotId] [int] NOT NULL,
    [Emote] [nvarchar](42) NOT NULL,
    [EmoteCountTypeId] [int] NOT NULL,
    [Count] [decimal](19, 6) NOT NULL,
    CONSTRAINT [PK_SnapshotsCrashproof] PRIMARY KEY CLUSTERED ([EmoteCountId] ASC) ON [PRIMARY],
    CONSTRAINT [FK_SnapshotsCrashproof_Snapshots] FOREIGN KEY ([SnapshotId]) REFERENCES [Snapshots].[Snapshots] ([SnapshotId]) ON DELETE CASCADE,
    CONSTRAINT [FK_SnapshotsCrashproof_EmoteCountTypes] FOREIGN KEY ([EmoteCountTypeId]) REFERENCES [dbo].[EmoteCountTypes] ([EmoteCountTypeId])
) ON [PRIMARY]
GO

这个代码插入其中：

using (SqlBulkCopy bulkCopy = new SqlBulkCopy(connection, SqlBulkCopyOptions.Default, trans))
{
    bulkCopy.DestinationTableName = "Snapshots.Crashproof";
    bulkCopy.ColumnMappings.Add(new SqlBulkCopyColumnMapping("SnapshotId", "SnapshotId"));
    bulkCopy.ColumnMappings.Add(new SqlBulkCopyColumnMapping("EmoteCountTypeId", "EmoteCountTypeId"));
    bulkCopy.ColumnMappings.Add(new SqlBulkCopyColumnMapping("Emote", "Emote"));
    bulkCopy.ColumnMappings.Add(new SqlBulkCopyColumnMapping("Count", "Count"));

    using (IDataReader reader = ObjectReader.Create(emoteCountTypesToSnapshot))
    {
        bulkCopy.WriteToServer(reader);
    }
}

它在99.99%的时间内运行良好（并且每分钟都进行批量复制），但是我确实遇到过一次异常，它出现在最后一行（bulkCopy.WriteToServer(reader);）：
违反PRIMARY KEY约束...无法在对象“Snapshots. Crashproof”中插入重复的键。重复的键值为（247125）。
我知道不推荐直接在final表中进行批量插入，我将修改代码，将其批量插入到临时表中，然后从那里插入。但这是导致此异常的原因吗？
我真的不明白一个重复的键怎么会出现在一个标识字段上：|