Oracle Apex 5.1动态SQL

Question

how to Dynamic SQL before report to users in Apex 5.1? my query is:

declare
    q varchar2(4000);
begin
    q := 'select * from tb1 t';
    if :Param1 is not null then
        q := q || ' where t.name = :Param1';
    end if;

return q;
end;

:Param1 is optional for users.

I want if :Param1 is null then my query execute without any where clause. otherwise set where clause in my query.

the point is my Apex is Version 5.1

Thanks

Answer 1

If that query is used as aa source for a report region, then you don't have to use dynamic SQL, but a simple OR condition:

select * 
from tb1 t
where (t.name = :param1 or :param1 is null)

The same would work elsewhere too.

Answer 2

you can use such a way below by using rowtype and type keywords for whole row and column values respectively :

SQL> set serveroutput on
SQL> declare
    q         varchar2(4000);
    rt        tb1%rowtype;
    i_name    tb1.name%type := 'Mohammad';
    o_surname tb1.surname%type;
begin
    q := 'select * from tb1 t';
    if i_name is not null then
        q := q || ' where ( t.name = :Param1 or :Param1 is null )'; 
    end if;
  execute immediate q into rt using i_name, i_name; 
 -- "i_name" appears twice because of ":Param1" appears twice in the string "q"
  o_surname := rt.surname;
  dbms_output.put_line(rt.surname);
end;

Taleshi

since there's only one parameter, then :Param1 is matched with i_name . If we had more than one parameter, then all should be matched in the appearance order of the bind parameters in the sql string with comma seperated variables such as i_name, .... in the using list.