using System.Data;
using System.Data.OleDb
then
String StrSql = "your sql query";
OleDbDataAdapter objDataAdapter = new OleDbDataAdapter(StrSql, sqlconnectionname);
DataSet objDataSet = new DataSet("ClientName");
objDataAdapter.Fill(objDataSet, "ClientName");
objDataAdapter.Dispose();
instead of OleDb we can use sqlclient accordingly