39在Oracle中表vendor包含以下列: Vendor_ID number primary key Name varchar30 Location_ID number Order_dt date Order_amount number82 下列对表vendor操作的语句合法的是选择2项aselect locaton_idavgorder_amountfrom vendor;b select
a)select locaton_id,avg(order_amount)from vendor; c) select sum(order_amount) from vendor;
a)open emp_cur; loop fetch emp_cur into p_emp; if emp_cur%found then dbms_output.put_line(‘Emp Name: