pg-unpivot.sql

create table rj (l1 int, l2 int, l3 int);
insert into rj values (0,0,0);
insert into rj values (1,1,1);
insert into rj values (1,0,1);
insert into rj values (0,1,0);
insert into rj values (1,0,0);

select * from rj;

 l1 | l2 | l3
----+----+----
  0 |  0 |  0
  1 |  1 |  1
  1 |  0 |  1
  0 |  1 |  0
  1 |  0 |  0
(5 rows)

select 'l'||t.i as label_name, t.label_val
from rj 
cross join lateral unnest(array[l1, l2, l3]) with ordinality as t(label_val,i);

label_name | label_val
------------+-----------
l1         |         0
l2         |         0
l3         |         0
l1         |         1
l2         |         1
l3         |         1
l1         |         1
l2         |         0
l3         |         1
l1         |         0
l2         |         1
l3         |         0
l1         |         1
l2         |         0
l3         |         0
(15 rows)

with t as (
  select 'l'||t.i as label_name, t.label_val
  from rj 
  cross join lateral unnest(array[l1, l2, l3]) with ordinality as t(label_val,i)
)
select
  label_name,
  sum(case when label_val = 0 then 1 else 0 end) as count_0,
  sum(case when label_val = 1 then 1 else 0 end) as count_1
from t
group by 1
order by 1;  

label_name | count_0 | count_1
------------+---------+---------
l1         |       2 |       3
l2         |       3 |       2
l3         |       3 |       2
(3 rows)