PL/SQL: Count how often a value appears and subtotal it

Question

I'm not the best at PL/SQL, but I'm trying and willing to learn.
I have some SQL that looks thru over 1 million rows in a DB and pulls back data and does decodes to make the data meaningful. My output looks like this right now
Row1 - Row2 - Row3 - Row4 - Row5
x a c d c
a c d b x
x c d b b
x x x a a
x a b b a
x = no answer
a = alpha
b = beta
c = charle
d = delta
My end goal is to try to do this: Is to try to figure out how many times x appears in a rows above, decode it from 'x' to 'no answer' and then spit out a subtotal. The same applies for A thru D as well.
Can anyone point out some PL/SQL examples that could help me out?
thanks

Answer 1

Two solutions
create table msw_emp
(id     varchar2(5),
row1     varchar2(1),
row2     varchar2(1),
row3     varchar2(1),
row4     varchar2(1),
row5     varchar2(1))
insert into msw_emp values('11111', 'x', 'a', 'c', 'd', 'a');
insert into msw_emp values('22222', 'x', 'a', 'a', 'd', 'd');
insert into msw_emp values('33333', 'x', 'x', 'x', 'a', 'x');
insert into msw_emp values('44444', 'a', 'a', 'a', 'a', 'b');
insert into msw_emp values('55555', 'x', 'x', 'x', 'x', 'x');
commit;
Answer Count
alpha - 9
beta - 1
charlie - 1
delta - 3
no answer - 11
#SOLUTION 1
select 'alhpa' "Answer Count",
sum(decode(row1, 'a', 1, 0)+
decode(row2, 'a', 1, 0)+
decode(row3, 'a', 1, 0)+
decode(row4, 'a', 1, 0)+
decode(row5, 'a', 1, 0)) a_count
from msw_emp
union all
select 'beta',
sum(decode(row1, 'b', 1, 0)+
decode(row2, 'b', 1, 0)+
decode(row3, 'b', 1, 0)+
decode(row4, 'b', 1, 0)+
decode(row5, 'b', 1, 0)) b_count
from msw_emp
union all
select 'charlie',
sum(decode(row1, 'c', 1, 0)+
decode(row2, 'c', 1, 0)+
decode(row3, 'c', 1, 0)+
decode(row4, 'c', 1, 0)+
decode(row5, 'c', 1, 0)) c_count
from msw_emp
union all
select 'delta',
sum(decode(row1, 'd', 1, 0)+
decode(row2, 'd', 1, 0)+
decode(row3, 'd', 1, 0)+
decode(row4, 'd', 1, 0)+
decode(row5, 'd', 1, 0)) d_count
from msw_emp
union all
select 'no answer',
sum(decode(row1, 'x', 1, 0)+
decode(row2, 'x', 1, 0)+
decode(row3, 'x', 1, 0)+
decode(row4, 'x', 1, 0)+
decode(row5, 'x', 1, 0)) x_count
from msw_emp
#SOLUTION 2
select decode(val,
'a', 'alpha',
'b', 'beta',
'c', 'charlie',
'd', 'delta',
'x', 'no answer')||' - '||count(*) "Answer Count"
from (select row1 val
from msw_emp
union all
select row2
from msw_emp
union all
select row3
from msw_emp
union all
select row4
from msw_emp
union all
select row5
from msw_emp)
group by val
Answer Count
alpha - 9
beta - 1
charlie - 1
delta - 3
no answer - 11