Oracle 18c

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select * from V$VERSION;


BANNER
BANNER_FULL
BANNER_LEGACY
CON_ID


Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
Version 18.4.0.0.0
Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
0


-- setup create 
create table transit (ordernum integer
                     ,cnum   integer
                     ,snum   integer
                     ,rec    date
                     ,ship   date
                     ,typ    varchar2(16)
                     ,inst   varchar2(4000)
                     ) ;
                    
 create table ord as 
        select ordernum,cnum,snum,rec,ship,typ
          from transit  
         where 1=0;
 create table ord2 as 
        select ordernum,cnum,snum,rec,ship,typ
          from transit  
         where 1=0;
insert into  transit(ordernum,cnum,snum,ship,typ) 
  select level                                    -- no meaning for any values just data
       , floor(dbms_random.value(2001,9367))     
       , floor(dbms_random.value(18750,56393))     
       , sysdate
       , '2 day'
    from dual connect by level <= 50; 
50 rows affected

select 'transit',count(*) from transit 
union all 
select 'ord',count(*) from ord 
union all
select 'ord2',count(*) from ord2 ; 


'TRANSIT'
COUNT(*)


transit
50

ord
0

ord2
0


-- Insert All 
create or replace 
procedure create_org_copies(successful_ot out boolean)   
is 
begin
   insert all 
       when mod(ordernum,2) = 1 then 
       into ord(ordernum,cnum,snum,rec,ship,typ)
          values(ordernum,cnum,snum,rec,ship,typ)
          
       when mod(ordernum,2) = 0 then
       into ord2(ordernum,cnum,snum,rec,ship,typ)
          values(ordernum,cnum,snum,rec,ship,typ)  
          
       select ordernum,cnum,snum,rec,ship,typ
         from transit; 

    successful_ot := true;                   
exception -- no exceptions to handle so log them all and return false
    when others then 
         -- log_proc_errors ( log parms )    -- whatever you use for logging exceptions 
         successful_ot := false;             -- normally either raise or raise_application_error
end create_org_copies;
/
declare 
   good_copy boolean;
begin 
    dbms_output.enable; 
    create_org_copies(good_copy);
    if good_copy
    then 
       dbms_output.put_line ( 'Transit copied successfully by create_org_copies.');
       commit; 
    else
       dbms_output.put_line ( 'Transit copiy failed in create_org_copies.');
       rollback;
    end if; 
end; 
/
1 rows affected

dbms_output:
Transit copied successfully by create_org_copies.

select 'transit',count(*) from transit 
union all 
select 'ord',count(*) from ord 
union all
select 'ord2',count(*) from ord2 ; 


'TRANSIT'
COUNT(*)


transit
50

ord
25

ord2
25


-- OP orig function
create or replace function new_func
  return boolean
is 
begin
   insert into ord(ordernum,cnum,snum,rec,ship,typ)
    select ordernum,cnum,snum,rec,ship,typ
    from transit;

   insert into ord2(ordernum,cnum,snum,rec,ship,typ)
       select ordernum,cnum,snum,rec,ship,typ
       from transit; 
       
   return true; 
end;
/
-- direct call from sql 
select new_func() from dual;
ORA-00902: invalid datatype

-- call from plsql block
begin
   dbms_output.enable; 
   if  new_func then 
       dbms_output.put_line ( 'Transit copied successfully by new_func.');
       commit; 
   else 
       dbms_output.put_line ( 'Transit copy failed in new_func.');
       rollback;  
    end if; 
end;
/
1 rows affected

dbms_output:
Transit copied successfully by new_func.

create or replace function new_func2
  return integer
is 
begin
   insert into ord(ordernum,cnum,snum,rec,ship,typ)
    select ordernum,cnum,snum,rec,ship,typ
    from transit;

   insert into ord2(ordernum,cnum,snum,rec,ship,typ)
       select ordernum,cnum,snum,rec,ship,typ
       from transit; 
       
   return 1; 
end new_func2;
/
-- direct call from sql 
select new_func2() from dual; 
ORA-14551: cannot perform a DML operation inside a query 
ORA-06512: at "FIDDLE_BDWLEOBJKFSLZUEEVNXH.NEW_FUNC2", line 5

-- call from plsql block   
begin
   dbms_output.enable; 
   if  new_func2() = 1 then 
       dbms_output.put_line ( 'Transit copied successfully by new_func2.');
       commit; 
   else 
       dbms_output.put_line ( 'Transit copy failed in new_func2.');
       rollback;  
    end if; 
end;
/
1 rows affected

dbms_output:
Transit copied successfully by new_func2.