how to insert DateTime.Now values into datetime type field in sql database

问题

my code is :

    SqlConnection cn = new SqlConnection("Data Source=.;Initial Catalog=haftehbazardb;Integrated Security=True ");
    SqlCommand cmd = cn.CreateCommand();


    cmd.CommandText = string.Format("Insert into Table_test(date1,date2) Values({0},{1})", DateTime.Now, DateTime.Now.AddDays(21));
    cn.Open();
    cmd.ExecuteNonQuery();

    cn.Close();

    Label1.Text = "Insert is done successfuly!";

I can insert evry type values into database.but i can not insert datetime.now or datetime.now.addday(21) into this database.type values date1 AND date2 is datetime.

回答1:

You should be using parameterized queries.

    cmd.CommandText = "Insert into Table_test(date1,date2) Values(@Now,@21DaysLater)";
    cmd.Parameters.AddWithValue("@Now", DateTime.Now);
    cmd.Parameters.AddWithValue("@21DaysLater", DateTime.Now.AddDays(21));

It would be a good idea to insert all of your values, not just DateTime using parameters. Don't use string concatenation to write SQL.

来源：https://stackoverflow.com/questions/27400750/how-to-insert-datetime-now-values-into-datetime-type-field-in-sql-database