looping in sql with delimiter - sql

Question

I just had this idea of how can i loop in sql?
For example
I have this column
PARAMETER_VALUE
E,C;S,C;I,X;G,T;S,J;S,F;C,S;
i want to store all value before (,) in a temp column also store all value after (;) into another column
then it wont stop until there is no more value after (;)
Expected Output for Example
COL1 E S I G S S C
COL2 C C X T J F S
etc . . .

Answer 1

You can get by using regexp_substr() window analytic function with connect by level <= clause
with t1(PARAMETER_VALUE) as
(
select 'E,C;S,C;I,X;G,T;S,J;S,F;C,S;' from dual
), t2 as
(
select level as rn,
regexp_substr(PARAMETER_VALUE,'([^,]+)',1,level) as str1,
regexp_substr(PARAMETER_VALUE,'([^;]+)',1,level) as str2
from t1
connect by level <= regexp_count(PARAMETER_VALUE,';')
)
select listagg( regexp_substr(str1,'([^;]+$)') ,' ') within group (order by rn) as col1,
listagg( regexp_substr(str2,'([^,]+$)') ,' ') within group (order by rn) as col2
from t2;
COL1 COL2
------------- -------------
E S I G S S C C C X T J F S
Demo

Answer 2

Assuming that you need to separate the input into rows, at the ; delimiters, and then into columns at the , delimiter, you could do something like this:
-- WITH clause included to simulate input data. Not part of the solution;
-- use actual table and column names in the SELECT statement below.
with
t1(id, parameter_value) as (
select 1, 'E,C;S,C;I,X;G,T;S,J;S,F;C,S;' from dual union all
select 2, ',U;,;V,V;' from dual union all
select 3, null from dual
)
-- End of simulated input data
select id,
level as ord,
regexp_substr(parameter_value, '(;|^)([^,]*),', 1, level, null, 2) as col1,
regexp_substr(parameter_value, ',([^;]*);' , 1, level, null, 1) as col2
from t1
connect by level <= regexp_count(parameter_value, ';')
and id = prior id
and prior sys_guid() is not null
order by id, ord
;
ID ORD COL1 COL2
--- --- ---- ----
1 1 E C
1 2 S C
1 3 I X
1 4 G T
1 5 S J
1 6 S F
1 7 C S
2 1 U
2 2
2 3 V V
3 1
Note - this is not the most efficient way to split the inputs (nothing will be very efficient - the data model, which is in violation of First Normal Form, is the reason). This can be improved using standard instr and substr, but the query will be more complicated, and for that reason, harder to maintain.
I generated more input data, to illustrate a few things. You may have several inputs that must be broken up at the same time; that must be done with care. (Note the additional conditions in CONNECT BY). I also illustrate the handling of NULL - if a comma comes right after a semicolon, that means that the "column 1" part of that pair must be NULL. That is shown in the output.