SQL Server中的DateTime2合并的精度与C＃的纳秒精度不同

Question

我在将DateTime插入SQL Server DateTime2(6)数据类型时遇到问题。我在C＃中有一个定义为Datetime的变量：

public DateTime CreatedOn { get; set; }

以下是我传递给SQL Server的日期：

当您注意到createdon上的刻度以786066结尾。但是我将上述datetime合并到SQL Server，并且在Update之后，我得到了不同的纳秒：

最后四位数字已更改。但是，当我在表上进行批量复制时，日期插入就很好了。但是当我逐行合并时，纳秒被错误地合并了。

MERGE [dbo].[ItemAttribute] as tgt
USING 
    (VALUES(@FK_ItemAttributeGroupCode, @ItemAttributeCode, @Name, @Description, 
            @EffectiveDate, @TerminationDate, @DataType, @DefaultString, 
            @DefaultNumeric, @DefaultDate, @FK_ItemGroupTypeCode, 
            @IsPublishable, @AttributeType, @IsAutoDelete, @IsFacilitySpecific, 
            @CreatedBy, @CreatedOn, @LastUpdatedBy, @LastUpdatedOn)) AS src ([FK_ItemAttributeGroupCode], [ItemAttributeCode], [Name], [Description], [EffectiveDate], [TerminationDate], [DataType], [DefaultString], [DefaultNumeric], [DefaultDate], [FK_ItemGroupTypeCode], [IsPublishable], [AttributeType], [IsAutoDelete], [IsFacilitySpecific], [CreatedBy], [CreatedOn], [LastUpdatedBy], [LastUpdatedOn])
     ON tgt.[FK_ItemAttributeGroupCode] = @FK_ItemAttributeGroupCode AND tgt.[ItemAttributeCode] = @ItemAttributeCode

WHEN MATCHED AND (EXISTS (SELECT TGT.[Name], TGT.[Description], TGT.[EffectiveDate], TGT.[TerminationDate], TGT.[DataType], TGT.[DefaultString], TGT.[DefaultNumeric], TGT.[DefaultDate], TGT.[FK_ItemGroupTypeCode], TGT.[IsPublishable], TGT.[AttributeType], TGT.[IsAutoDelete], TGT.[IsFacilitySpecific], TGT.[CreatedBy], TGT.[CreatedOn], TGT.[LastUpdatedBy], TGT.[LastUpdatedOn] EXCEPT SELECT @Name, @Description, @EffectiveDate, @TerminationDate, @DataType, @DefaultString, @DefaultNumeric, @DefaultDate, @FK_ItemGroupTypeCode, @IsPublishable, @AttributeType, @IsAutoDelete, @IsFacilitySpecific, @CreatedBy, @CreatedOn, @LastUpdatedBy, @LastUpdatedOn))  
    THEN
       UPDATE 
           SET [FK_ItemAttributeGroupCode] = @FK_ItemAttributeGroupCode, [ItemAttributeCode] = @ItemAttributeCode, [Name] = @Name, [Description] = @Description, [EffectiveDate] = @EffectiveDate, [TerminationDate] = @TerminationDate, [DataType] = @DataType, [DefaultString] = @DefaultString, [DefaultNumeric] = @DefaultNumeric, [DefaultDate] = @DefaultDate, [FK_ItemGroupTypeCode] = @FK_ItemGroupTypeCode, [IsPublishable] = @IsPublishable, [AttributeType] = @AttributeType, [IsAutoDelete] = @IsAutoDelete, [IsFacilitySpecific] = @IsFacilitySpecific, [CreatedBy] = @CreatedBy, [CreatedOn] = @CreatedOn, [LastUpdatedBy] = @LastUpdatedBy, [LastUpdatedOn] = @LastUpdatedOn

WHEN NOT MATCHED 
   THEN
      INSERT([FK_ItemAttributeGroupCode], [ItemAttributeCode], [Name], [Description], [EffectiveDate], [TerminationDate], [DataType], [DefaultString], [DefaultNumeric], [DefaultDate], [FK_ItemGroupTypeCode], [IsPublishable], [AttributeType], [IsAutoDelete], [IsFacilitySpecific], [CreatedBy], [CreatedOn], [LastUpdatedBy], [LastUpdatedOn]) 
      VALUES(@FK_ItemAttributeGroupCode, @ItemAttributeCode, @Name, @Description, @EffectiveDate, @TerminationDate, @DataType, @DefaultString, @DefaultNumeric, @DefaultDate, @FK_ItemGroupTypeCode, @IsPublishable, @AttributeType, @IsAutoDelete, @IsFacilitySpecific, @CreatedBy, @CreatedOn, @LastUpdatedBy, @LastUpdatedOn);

我们正在使用SQL Server 2016。

foreach (var entity in entities)
                {
                    try
                    {
                        await conn.ExecuteAsync(sql, commandType: CommandType.Text, param: entity, commandTimeout: SQLCommandTimeOut);
                    }
}

Sql具有以上合并查询，我将实体作为参数传递，并且实体上的CreatedOn为DateTime。但是，如果我们使用C＃的BulkCopy，而不是循环并插入到表中，则可以使用实际的DateTime C＃将其正确插入，直到n＃秒为止，但是如果您注意到上面的屏幕截图，则逐行插入的最后4位nano秒是不同的。 / p>

对此有任何帮助吗？