Oracle view: how to obtain a column definition - oracle

Question

I have an Oracle view:
create view schemaName.viewName as
select case when 1=1 then 1 else 2 end as col1, decode('A','A','B','C') as col2 from dual
Is there a way to obtain an output or a table with this information:
Column_Name: Col1
Column_Definition: case when 1=1 then 1 else 2 end
Column_Name: Col2
Column_Definition: decode('A','A','B','C')
Thank you very much

Answer 1

Here is the below anonymous block to get column name and column definition for above view.
DECLARE
a varchar2(1000);
b varchar2(1000);
c varchar2(1000);
BEGIN
EXECUTE IMMEDIATE 'SELECT TEXT FROM user_views
WHERE VIEW_NAME=''TEST_VW'' ' INTO a;
SELECT regexp_replace(regexp_substr(a, '^[^,]*'),'select|as\W','') -- getting first argument case to get "case when 1=1 then 1 else 2 end col1"
into b from dual;
DBMS_OUTPUT.PUT_LINE( 'Column_Name: '|| regexp_substr(b,'[^ ]+$')); -- this command to get last col1 from "case when 1=1 then 1 else 2 end col1"
DBMS_OUTPUT.PUT_LINE('Column_Definition: '|| regexp_replace(b,'[^ ]+$','')); -- this command to make col1 to empty to get column definition
select regexp_replace(substr(a,length(regexp_substr(a, '^[^,]*'))+2),'select|dual|from|as\W','') into c from dual; -- this command to get 2nd column "decode('A','A','B','C') col2"
DBMS_OUTPUT.PUT_LINE( 'Column_Name: '|| REGEXP_SUBSTR ( c , '[^ ]+' , 1 , 2 )); -- This command will get 2nd column col2 from "decode('A','A','B','C') col2"
DBMS_OUTPUT.PUT_LINE( 'Column_Definition: '|| REGEXP_SUBSTR ( c , '[^ ]+' , 1 , 1 )); -- This command will get 1st column decode('A','A','B','C') from "decode('A','A','B','C') col2"
END;

Answer 2

Thanks for clarifying ... just try below block and see if this helps ..Also let me know for any column definition which is incorrect
prerequiste for ananymous block:
create view TEST_VW as
select case when 1=1 then 1 else 2 end as col1, decode('A','A','B','C') as col2,
null as col3 , sysdate as col4 , 'var1' as col5
from dual;
-- In view definition I hope a format of each column as and separator of each columns is key to separate the column name and definition for this block.
create sequence seq
start with 1;
create table col_nm_def
(column_nm varchar2(1000),
column_def varchar2(1000),
id number);
Ananymous block;
DECLARE
a varchar2(1000);
b varchar2(1000);
c varchar2(1000);
d number;
BEGIN
EXECUTE IMMEDIATE 'SELECT TEXT FROM user_views
WHERE VIEW_NAME=''TEST_VW'' ' INTO a;
EXECUTE IMMEDIATE 'delete from col_nm_def';
EXECUTE IMMEDIATE 'drop sequence seq';
EXECUTE IMMEDIATE 'create sequence seq
start with 1';
select regexp_replace(regexp_replace(a,'select|from|dual',''),'as\W|, ' , '|') into b from dual; -- replacing as and (, ) to | symbol (try to change symbol if view uses this pipe in transformation)
select regexp_count(b,'[|]') into d from dual;
d:=d+1;
For i in 1..d
LOOP
insert into col_nm_def values (REGEXP_SUBSTR ( b , '[^|]+' , i+1 , i+1 ),REGEXP_SUBSTR ( b , '[^|]+' , i , i ),seq.nextval);
COMMIT;
END LOOP;
END;
Final result : select only odd rows
select * from col_nm_def where mod(id,2)=1 order by ID;