Convert a series of Number values in Text in Oracle SQL Query - sql

Question

In the Oracle database, I have string values (VARCHAR2) like 1,4,7,8. The number represents as 1=car, 2= bus, 3=BB, 4=SB, 5=Ba, 6=PA, 7=HB, and 8 =G
and want to convert the above-said example to "car,SB,HB,G" in my query results
I tried to use "Decode" but it does not work. Please advise how to make it works. Would appreciate.
Thanks`
Initially, I have used the following query:
Select Clientid as C#, vehicletypeExclusions as vehicle from
clients
The sample of outcomes are:
C# Vehicle
20 1,19,20,23,24,7,5
22 1,19,20,23,24,7,5
I also tried the following that gives me the null value of vehicles:
Select Clientid as C#, Decode (VEHICLETYPEEXCLUSIONS, '1', 'car',
'3','bus', '5','ba' ,'7','HB', '8','G'
, '9','LED1102', '10','LED1104', '13','LED8-2',
'14','Flip4-12', '17','StAT1003', '19','Taxi-Min', '20','Tax_Sed',
'21','Sup-veh' , '22','T-DATS', '23','T-Mini',
'24','T-WAM') as vehicle_Ex from clients >

Answer 1

Here's one option. Read comments within code. Sample data in lines #1 - 13; query begins at line #14.
SQL> with
2 expl (id, name) as
3 (select 1, 'car' from dual union all
4 select 2, 'bus' from dual union all
5 select 3, 'BB' from dual union all
6 select 4, 'SB' from dual union all
7 select 5, 'Ba' from dual union all
8 select 6, 'PA' from dual union all
9 select 7, 'HB' from dual union all
10 select 8, 'G' from dual
11 ),
12 temp (col) as
13 (select '1,4,7,8' from dual),
14 -- split COL to rows
15 spl as
16 (select regexp_substr(col, '[^,]+', 1, level) val,
17 level lvl
18 from temp
19 connect by level <= regexp_count(col, ',') + 1
20 )
21 -- join SPL with EXPL; aggregate the result
22 select listagg(e.name, ',') within group (order by s.lvl) result
23 from expl e join spl s on s.val = e.id;
RESULT
--------------------------------------------------------------------------------
car,SB,HB,G
SQL>

Answer 2

Using the function f_subst from https://stackoverflow.com/a/68537479/429100 :
create or replace
function f_subst(str varchar2, template varchar2, subst sys.odcivarchar2list) return varchar2
as
res varchar2(32767):=str;
begin
for i in 1..subst.count loop
res:=replace(res, replace(template,'%d',i), subst(i));
end loop;
return res;
end;
/
I've replaced ora_name_list_t (nested table) with sys.odcivarchar2list (varray) to make this example easier, but I would suggest to create your own collection for example create type varchar2_table as table of varchar2(4000);
Example:
select
f_subst(
'1,4,7,8'
,'%d'
,sys.odcivarchar2list('car','bus','BB','SB','Ba','PA','HB','G')
) s
from dual;
S
----------------------------------------
car,SB,HB,G

Answer 3

Assume you have a lookup table (associating the numeric codes with descriptions) and a table of input strings, which I called sample_inputs in my tests, as shown below:
create table lookup (code, descr) as
select 1, 'car' from dual union all
select 2, 'bus' from dual union all
select 3, 'BB' from dual union all
select 4, 'SB' from dual union all
select 5, 'Ba' from dual union all
select 6, 'PA' from dual union all
select 7, 'HB' from dual union all
select 8, 'G' from dual
;
create table sample_inputs (str) as
select '1,4,7,8' from dual union all
select null from dual union all
select '3' from dual union all
select '5,5,5' from dual union all
select '6,2,8' from dual
;
One strategy for solving your problem is to split the input - slightly modified to make it a JSON array, so that we can use json_table to split it - then join to the lookup table and re-aggregate.
select s.str, l.descr_list
from sample_inputs s cross join lateral
( select listagg(descr, ',') within group (order by ord) as descr_list
from json_table( '[' || str || ']', '$[*]'
columns code number path '$', ord for ordinality)
join lookup l using (code)
) l
;
STR DESCR_LIST
------- ------------------------------
1,4,7,8 car,SB,HB,G
3 BB
5,5,5 Ba,Ba,Ba
6,2,8 PA,bus,G