How do you map TimeStamp (SQL Server) to DateTime (.NET) datatype? I ran into the following error:

"Could not cast the value in field ts_times4_ to the Type TimestampType. Please check to make sure that the mapping is correct and that your DataProvider supports this Data Type."

My table:
CREATE TABLE [some_table] (
[field1] [int] NOT NULL ,
... other fields ...
[ts_timestamp] [timestamp] NULL ,
.... other fields ...
) ON [PRIMARY]

My class:

Namespace ....

Public Class AtDivision
... other properties ...
Protected _timestamp As DateTime

' How do I map to data type 'Timestamp'?
Public Property Timestamp() As DateTime
....
End Property

End Class

I tried this in my mapping file, but, ran into the error I mentioned...
property name="Timestamp" column= "ts_timestamp" type="Timestamp"

Guys... Anyone? Show me the light :(

I'm not 100 percent sure. But, I can tell you that a 'timestamp' data type in SQL Server 2000 is NOT the same as DateTime. I think it would be equivelent to a binary(16).

An SQL Server timestamp maps to a .NET System.Byte[]; it should be handled as an NH BinaryType. However, timestamp isn't listed as a type in the SQL 2k dialect - possibly because it's not updateable? I'm not sure whether the dialect is just used to reflect types from the database.

A timestamp column is not particularly useful to you if you can't use it for optimistic concurrency checking though - I haven't yet worked out how to do this (see my database row versioning topic).

Sorry - re-reading the original post, I wasn't very clear.

An SQL Server timestamp is IMO very confusingly named as it does not contain any date or time data. Microsoft now prefer that you use the 'rowversion' synonym instead of 'timestamp'. Think of it as a read-only GUID (binary(8)) that the database changes each time there's a row update.

If you want to store date & time data, use a datetime column instead of timestamp.

Cheers,
Sam.