ORA-01422 Error While Doing Insert

Question

Hello,
I am trying to do a insert using the following code
declare
i number;
ret varchar2(1000);
ret2 varchar2(1000);
ret3 varchar2(1000);
begin
FOR I IN 1..20 LOOP
select sl_no ,ename,addr into ret,ret2,ret3
from
(select u.sl_no as sl_no,
(select ename from table where sl=1  and des  = 1 ) as ename ,
T.addr as addr  from
tab1 t,tab2  u
where
U.cd = T.cd
and U.code = T.code and U.sl=0+i
union all
select u.sl_no as sl_no,
(select ename from table where sl=1  and des  = 1 ) as ename ,
T.addr as addr  from
tab1 t,tab2  u
where
U.cd = T.cd
and U.code = T.code and U.sl=0+i);However I am getting error
ORA-01422: exact fetch returns more than requested number of rowsHow could I resolve this problem
Thanks

Answer 1

@OP,
Some of the points in your "FULL CODE".
1.You are selecting in a FOR I 1..20 LOOP... The SELECT statement has INTO clause. With UNION (ALL) may be you are expecting (and getting) more than one row in which case you need to define cursor and fetch from the cursor .
2. You have a COMMIT within the loop, it may be ok if you want to commit 20 times! In general, Please commit when the logical unit of work (LUW) is completed. In my experience LUW is normally not completed within a loop.
3. Why even have a LOOP and PL/SQL procedural code?
Why not do the following...
insert into my_table(sl_no,ename,addr)
select sl_no ,ename,addr into ret,ret2,ret3
     from
     (select u.sl_no as sl_no,
     (select ename from table where sl=1  and des  = 1 ) as ename ,
     T.addr as addr  from
     tab1 t,tab2  u
     where
     U.cd = T.cd
     and U.code = T.code and U.sl=0+i
     union all
     select u.sl_no as sl_no,
     (select ename from table where sl=1  and des  = 1 ) as ename ,
     T.addr as addr  from
     tab1 t,tab2  u
     where
     U.cd = T.cd
     and U.code = T.code and U.sl=0+i);4. If you absolutely have to have PL/SQL code try something like folloing...
declare
i number;
ret varchar2(1000);
ret2 varchar2(1000);
ret3 varchar2(1000);
begin
FOR I IN 1..20 LOOP
  FOR x in (              -- "Added"
     select sl_no ,ename,addr into ret,ret2,ret3
     from
     (select u.sl_no as sl_no,
     (select ename from table where sl=1  and des  = 1 ) as ename ,
     T.addr as addr  from
     tab1 t,tab2  u
     where
     U.cd = T.cd
     and U.code = T.code and U.sl=0+i
     union all
     select u.sl_no as sl_no,
     (select ename from table where sl=1  and des  = 1 ) as ename ,
     T.addr as addr  from
     tab1 t,tab2  u
     where
     U.cd = T.cd
     and U.code = T.code and U.sl=0+i)
   LOOP ;                -- "Added"
   insert into my_table(sl_no,ename,addr)
   values (ret,ret2,ret3);
end loop;               -- "Added"
commit;
end loop;
end;vr,
Sudhakar B.