Oracle modifiable cursor example

Source code:

Declare
Cursor C1
Is
Select *
From Src_list
For   Update   Of Callednum,
Businessnum,
Startdate,
Starttime,
Duration,
Unitnumber,
Break;

V_callednum Varchar2 ( 20 );
V_startdate Char ( 8 );
V_starttime Char ( 6 );
V_duration Number ( 10 );
V_unitnumber Number ( 7 );
V_133 Number ( 8 );
Begin
For R In C1
Loop
Select Called168
Into V_callednum
From ( Select Called168
From Called168
Order   By Dbms_random.value)
Where Rownum =   1 ;

Select   ' 200611 '   | To_char (trunc (dbms_random.value ( 10 , 30 )))
Into V_startdate
From Dual;

Select Lpad (to_char (trunc (dbms_random.value ( 9 , 20 ))), 2 , ' 0 ' )
| Lpad (to_char (trunc (dbms_random.value ( 1 , 59 ))), 2 , ' 0 ' )
| Lpad (to_char (trunc (dbms_random.value ( 1 , 59 ))), 2 , ' 0 ' )
Into V_starttime
From Dual;

Select Trunc (dbms_random.value ( 120 , 480 ))
Into V_duration
From Dual;

Select Ceil (v_duration /   60 )
Into V_unitnumber
From Dual;

V_1: = V_unitnumber *   200 ;

Update Src_list
Set Callednum = V_callednum,
Businessnum = V_callednum,
Startdate = V_startdate,
Starttime = V_starttime,
Duration = V_duration,
Unitnumber = V_unitnumber,
Bytes = V_133
Where   Current   Of C1;
End Loop;

Commit ;
End ;