Access日期查詢

sqlWhere = "where start_date <= # " + string.Format("{0:dd/MM/yyyy}", dtp1.Value) + " #";
sqlWhere = "where start_date >= # " + string.Format("{0:dd/MM/yyyy}", dtp1.Value) + " #";
sqlWhere = "where start_date = # " + string.Format("{0:dd/MM/yyyy}", dtp1.Value) + " #";
sqlWhere = "where start_date between # " + string.Format("{0:dd/MM/yyyy}", dtp1.Value) + " # and # " + string.Format("{0:dd/MM/yyyy}", dtp2.Value) + " #";