SQL & PL/SQL

Hi,

create table table_1 (num number)

create or replace function function_a return number
  is
    l_rv number;
  begin
    l_rv := dbms_random.value();
    insert into table_1 values(l_rv);
    return l_rv;
  end;

select function_a from dual

Now i am getting the error:

ORA-14551: cannot perform a DML operation inside a query

ORA-06512: at "FUNCTION_A", line 6

create table table_2 (num number)

insert into table_2 select function_a from dual

Now am not getting the same error. It is inserting records into table_2

Can anyone please clarify this?

Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production

Message was edited by: O-O added : (select function_a from dual)