Pagination Limit the number of result from query. If exceed throw error

Question

Hi expert,
I have a question that need your guidance.
Declare
    type myarray is table of emp.empid%type;
    mytab myarray;
    vcounter number;
    vlimit number;
Begin
    select limitnumber into vlimit from ABC where table_name = 'XYZ';
    select count(*) into vcounter from emp where empid = 1 /*let say this return 5500 records and take 10 seconds*/
    if vcounter > 5000 then
       raise_application_error(-20010,'you will process more than allowed number of record');
    else
        select empid bulk collect into mytab where empid = 1; /*let say this will take another 10 seconds for 5000 records*/
    end if
End;
/as you see there, if I want to insert 5000 records it will take me 10 sec to count first and then another 10 sec to insert.
I am trying to avoid the count to save time, but how to limit if the array insertion to 5000 otherwise throw the error.
please note that we limit the limitnumber in table ABC and that can be changed.
thanks
Henk
Edited by: user9180414 on Oct 19, 2011 12:57 PM

Answer 1

If you want to select just first 5000 rows use LIMIT:
select empid bulk collect into mytab limit 5000 where empid = 1;If you also want to make sure there is no more than 5000 rows use:
select empid bulk collect into mytab limit 5001 where empid = 1;
if mytab(5001). exists then
raise_application_error(-20010,'you will process more than allowed number of record');
end if;SY.