How to update the columns using sql queries?

Question

create table emp(eno number(5),ename varchar2(20),dno number(2),dname varchar2(20),loc_id number(3), location varchar2(10));
insert into emp(eno,ename,dno,loc_id) values(1,'tom1',10,1);
insert into emp(eno,ename,dno,loc_id) values(2,'tom2',20,2);
insert into emp(eno,ename,dno,loc_id) values(3,'tom3',30,3);
insert into emp(eno,ename,dno,loc_id) values(4,'tom4',40,4);
insert into emp(eno,ename,dno,loc_id) values(5,'tom5',50,5);
insert into emp(eno,ename,dno,loc_id) values(6,'tom6',60,6);
insert into emp(eno,ename,dno,loc_id) values(7,'tom7',70,7);
insert into emp(eno,ename,dno,loc_id) values(8,'tom8',80,8);
create table dept(dno number(3),dname varchar2(10));
insert into dept values(10,'RM');
insert into dept values(10,'DD');
insert into dept values(10,'TD');
create table location(loc_id number(3),location varchar2(20));
insert into location values(1,'palani');
insert into location values(1,'salem');
insert into location values(1,'kalpattu');
insert into location values(1,'thirukoyilur');
insert into location values(2,'thaeni');
insert into location values(2,'villupuram');
insert into location values(2,'yercaud');
insert into location values(3,'thiruvanamalai');
insert into location values(3,'trichy');
insert into location values(7,'tanjore');
insert into location values(4,'tirunelveli');
insert into location values(4,'namakal');
insert into location values(5,'bangalore');
insert into location values(6,'chennai');
insert into location values(6,'calcutta');
insert into location values(7,'tirupathy');
insert into location values(7,'bombay');
insert into location values(7,'kumbokonam');
My requirement is to update the department name and location of toms present in employee table without using cursors, loops.
The column department number and loc_id are used for joins.
I am in a situation to deliver my code on time.

Answer 1

try this
update emp tt
set (dname,location ) = (
select res,res1 from (select a.eno,a.ename,a.dno,b.dname,a.loc_id,c.location
from emp a,
dept b,
location c
where a.dno = b.dno
and a.loc_id = c.loc_id
) t
where tt.eno = t.eno
model
return updated rows
partition by (eno)
dimension by (row_number() over (order by eno) as rn)
measures(cast (dname as varchar2(50))  as res,cast (location as varchar2(300)) as res1)
rules
upsert
iterate(1000)
until(presentv(res[iteration_number + 2],1,0) = 0)
res[0] = res[0] ||','|| res[iteration_number + 1],
res1[0] = res1[0] ||','|| res1[iteration_number + 1]))
;output
1     tom1     10     ,RM,RM,RM,RM,DD,TD,DD,DD,TD,TD,TD,DD     1     ,palani,salem,kalpattu,thirukoyilur,palani,thirukoyilur,kalpattu,thirukoyilur,palani,salem,kalpattu,salem
2     tom2     20          2     
3     tom3     30          3     
4     tom4     40          4     
5     tom5     50          5     
6     tom6     60          6     
7     tom7     70          7     
8     tom8     80          8