Converting a numerical code into a word string right-to-left - sql

Question

I am trying to use an SQL select expression to convert the following from 1st column, into the 2nd.
Code Outcome
88881133 Species 1, 2, 3, 4 sick
88888888 NULL
88888833 Species 1, 2 sick
88888811 Species 1, 2 sick
88888111 Species 1, 2, 3 sick
88888881 Species 1 sick
Code should be read from right to left.
1 or 3 means that the Species is sick.
8 means Species is not sick.
I suppose it involves some CASE expression, but I couldn't go very further than:
SELECT
CASE WHEN RIGHT(Code, 1) = 1 OR WHEN RIGHT(Code, 1) = 3
THEN 'Species 1 sick' END AS Outcome
FROM table
I use the Vertica database

Answer 1

Here is another method just using like and case. I'm just translating 1 and 3 to 1, and 8 to 0. Mostly because I was going to do a binary method but this seemed simpler. The real reason is just to keep the case statement simple (else you have to check both 1 and 3 cases).
The rtrim has a second parameter meaning to trim only that extra comma space. It's a simple trick to remove the last one. The outer case is just making sure there are species (otherwise it'll return null).
Hope it helps.
with translated_mytable as (
select code, translate(code,'813','011') newcode
from mytable
)
select Code,
case when newcode like '%1%' then
'Species ' ||
rtrim(case when newcode like '_______1' then '1, ' else '' end ||
case when newcode like '______1_' then '2, ' else '' end ||
case when newcode like '_____1__' then '3, ' else '' end ||
case when newcode like '___ 1___' then '4, ' else '' end ||
case when newcode like '___1____' then '5, ' else '' end ||
case when newcode like '__1_____' then '6, ' else '' end ||
case when newcode like '_1______' then '7, ' else '' end ||
case when newcode like '1_______' then '8, ' else '' end,
', ') || ' sick'
end Outcome
from translated_mytable

Answer 2

Please, try that query - it should do the trick - please just change t_tab into your_table_name and it should work
WITH
t_tab2 AS
(
SELECT t.code,
CASE WHEN SUBSTR(t.code,1,1) IN (1,2,3) THEN 8 END Out1,
CASE WHEN SUBSTR(t.code,2,1) IN (1,2,3) THEN 7 END Out2,
CASE WHEN SUBSTR(t.code,3,1) IN (1,2,3) THEN 6 END Out3,
CASE WHEN SUBSTR(t.code,4,1) IN (1,2,3) THEN 5 END Out4,
CASE WHEN SUBSTR(t.code,5,1) IN (1,2,3) THEN 4 END Out5,
CASE WHEN SUBSTR(t.code,6,1) IN (1,2,3) THEN 3 END Out6,
CASE WHEN SUBSTR(t.code,7,1) IN (1,2,3) THEN 2 END Out7,
CASE WHEN SUBSTR(t.code,8,1) IN (1,2,3) THEN 1 END Out8
FROM t_tab t
)
SELECT tt.code,
CASE WHEN tt.out1||tt.out2||tt.out3||tt.out4||
tt.out5||tt.out6||tt.out7||tt.out8 IS NULL THEN NULL
ELSE REGEXP_REPLACE(
REGEXP_REPLACE(RTRIM('Species' || ' ' || tt.out8 || ', ' || tt.out7|| ', '
|| tt.out6 || ', ' || tt.out5 || ', '
|| tt.out4 || ', ' || tt.out3 || ', '
|| tt.out2 || ', ' || tt.out1, ', ')
|| ' sick', ', | ,', ','), ',{1,}', ', ') END AS Outcome
FROM t_tab2 tt
It's giving me the result:
1 88881133 Species 1, 2, 3, 4 sick
2 88888888
3 88888833 Species 1, 2 sick
4 88888811 Species 1, 2 sick
5 88888111 Species 1, 2, 3 sick
6 88888881 Species 1 sick