C# .NET - selecting rows from table based on system date

HI
i want to select some rows from my table based on the default system date or specific date . i am using c# with the back end sql server.

below my code which i tried, but not able to select the rows. i am in trouble

DateTime attdate = System.DateTime.Now;

sda = new SqlDataAdapter("select distinct empid from tbl_machineio where udate = '" + attdate + "' order by empid", conn);
 
i dont know how to solve this.

thanks in advance

use queries with parameter instead of plain sql, which will prevent sql injections. Also check whether your store time in the database column specified. 

SqlCommand cmd = new SqlCommand("SELECT * FROM table_name WHERE dateTimeField = @SomeDate");

cmd.Parameters.AddWithValue("@SomeDate", DateTime.Today);

Thanks for ur help. it works fine.