Data type mismatch in criteria expression | Access, OleDb, C#

Question

I read/update data from MS Access using C#. My code is:

public static void UpdateLastLogin(int userid, DateTime logintime) ///logintime = DateTime.Now
{
    string sql = @"UPDATE [Customers] SET [LastLogin]=?";
    OleDbParameter[] prms = new OleDbParameter[] { 
     new OleDbParameter("@LastLogin",logintime)
    };
    using (DAL dal = new DAL())
    {
        dal.UpdateRow(sql, false, prms);
    }
}

When it comes to Dates, I having trouble. This throws a "Data type mismatch in criteria expression." error. (I removed WHERE clause for keeping it simpler) Am I suuposed to enclose [LastLogin]=? question mark with single quotes, # signs .. does not help. Any leads on how to handle DateTime objects with Access and OleDb provider will be greatly appreciated.

Thanks in advance.

Answer 1

There is a known issue with OleDb and dates. Try doing something like:

OleDbParameter p = parameter as OleDbParameter;
if (null == p)
  parameter.DbType = DbType.DateTime;
else
  p.OleDbType = OleDbType.Date;

Or use explicit format string:

value.ToString("yyyy-MM-dd hh:mm:ss")

Answer 2

I solved this using the following code

OleDbCommand cmd = new OleDbCommand(qry, cnn);
cmd.Parameters.Add("datenow", OleDbType.Date);
cmd.Parameters["datenow"].Value = DateTime.Now;