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

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 [LastLog开发者_StackOverflow中文版in]=? 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.

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")

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;

Firstly, no your SQL statement should be:

"UPDATE Customers SET LastLogin=@LastLogin"

Secondly, the reason you are receiving the date mismatch error will probably be your passing '?' as your date time into the LastLogin field instead of the actual logintime parameter.

maybe try

DateTime.Now.ToShortDateString() + ' ' + DateTime.Now.ToShortTimeString()

instead, pass it as String (and maybe enclose with # then)

Should it not be

"UPDATE Customers SET LastLogin='@LastLogin'"

And @LastLogin should be

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

edit Could you not just inline the whole thing?

"UPDATE Customers SET LastLogin='" + logintime.ToString("yyyy-MM-dd hh:mm:ss") + "'"

Try setting the "DBTYPE" property of the parameter to identify it as a date, datetime or datetime2 as appropriate...

prms[0].DbType = DbType.DateTime;

There are 7 signatures to the new OleDbParameter() call, so you may change the signature instance, or just do explicitly as I sampled above since you only had 1 parameter in this case.