无法将参数值从TimeSpan转换为DateTime [英] Failed to convert parameter value from a TimeSpan to a DateTime

问题描述

我正在尝试从文本框字段值存储时间，但出现此异常错误，我在做什么错呢?谢谢！:

I am trying to store a time from my textbox field value but I got this exception error, what am I doing wrong? Thanks!:

Failed to convert parameter value from a TimeSpan to a DateTime.

传递文本框值:

.CamActiveDateFrom = CDate(uitxtCamDateStart.Text.Trim)

我的变量和属性:

Private _camActiveTimeFrom As Nullable(Of TimeSpan)

Public Property CamActiveTimeFrom() As Nullable(Of TimeSpan)

Get     

Return Me._camActiveTimeFrom        

End Get     

Set(ByVal value As Nullable(Of TimeSpan))            

Me._camActiveTimeFrom = value      

End Set    

End Property

参数:

 AddInParameter(dbCommand,

    "@ActiveTimeFrom", DbType.Time, 6, DBNull.Value)                

    If (.CamActiveTimeFrom).HasValue Then

     dbCommand.Parameters("@ActiveTimeFrom").Value = .CamActiveTimeFrom     

End If

推荐答案

DbType.Time 记录为:

代表SQL Server DateTime值的类型.如果要使用SQL Server时间值，请使用 SqlDbType.Time .

所以或者都使用 SqlDbType.Time ，将或的值设置为 DateTime 的值，而不是 TimeSpan 值.

So either use SqlDbType.Time instead, or set the value to a DateTime value instead of a TimeSpan value.

必须此映射表显示 DbType.Time映射到 TimeSpan ，因此这里存在一些不一致之处-但是，如果您可以使用更具体的类型，那就太好了.

Admittedly this mapping table show the DbType.Time mapping to TimeSpan, so there's some inconsistency here - but if you can use a more specific type, that can only be good.

当然，如果愿意的话，可以很容易地从 TimeSpan 构造一个 DateTime -您可能应该确定一个始终使用的特定日期(例如2000年1月1日)这样您就可以比较数据库中的值并有效地进行时间位的比较.

Of course it's easy to construct a DateTime from a TimeSpan if you want to - you should probably decide on a specific date to always use (e.g. 1st January 2000) so that you can then compare values within the database and effectively get a comparison of just the time bits.

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