Question

I have a C# DateTime class and wanted to know how I need to format it in a SQL Server CE query to insert it into the database, I was hoping to have both the date and time inserted in. Currently when I try variations thereof I get invalid format exceptions.

Current format I’m using is: dd/MM/yyyy, was hoping to do something like dd/MM/yyyy hh:mm:ss.

The way I’m trying to do the insert is like so:

 ( ( DateTime )_Value ).ToString( "dd/MM/yyyy hh:mm:ss" )

Obviously hh:mm:ss isn’t working, if that isn’t there dd/MM/yyyy executes successfully in the query.

I’ve tried a few formats including what I’ve found on google but none have worked so far…

Answer 1

If you’re worried about getting the format right at all, something has already gone seriously wrong. There are two things you need to do to correctly work with datetime values in any database, not just sqlce:

1. Make sure you’re using a datetime type for the column (not a text type like varchar)
2. Make sure you’re using a datetime parameter in a parameterized query, and not string concatenation.

If you do that, there is no formatting involved on your part. At all. Example:

 void SetDate(int recordID, DateTime timeStamp)
 {
    string SQL = "UPDATE [sometable] SET someDateTimeColumn= @NewTime WHERE ID= @ID";

    using (var cn = new SqlCeConnection("connection string here"))
    using (var cmd = new SqlCeCommand(SQL, cn))
    {
        cmd.Parameters.Add("@NewTime", SqlDbType.DateTime).Value = timeStamp;
        cmd.Parameters.Add("@ID", SqlDbType.Integer).Value = recordID;

        cn.Open();
        cmd.ExecuteNonQuery();
    }
} 

Never ever ever ever EVER use string manipulation to substitute values into sql queries. It’s a huge no-no.