SQL Select Like Column Name from table - sql

Question

The goal is to create a Oracle Function that is capable of query column name off a token provided by the user as to create a function with such capabilities
select cols_like('%e%') from table
This is the point I am currently at
CREATE OR REPLACE Function COLS_LIKE
(v_search in VARCHAR2, v_table in VARCHAR2)
RETURN VARCHAR
IS
TYPE r_cursor IS REF CURSOR;
c_emp r_cursor;
crs_cols VARCHAR(255);
column_list VARCHAR(1000);
BEGIN
OPEN c_emp FOR
'select COLUMN_NAME from cols
where TABLE_NAME = ''' || v_table || '''
and column_name like ''' || v_search || '''';
LOOP
FETCH c_emp INTO crs_cols;
EXIT WHEN c_emp%NOTFOUND;
if column_list IS NULL THEN
column_list := crs_cols;
else
column_list := column_list || ', ' || crs_cols;
end if;
END LOOP;
RETURN column_list;
END;
Where you call the function such as this
Declare
tests VARCHAR(100);
sql_stmt VARCHAR2(200);
begin
tests := COLS_LIKE('%E%', 'table');
DBMS_OUTPUT.PUT_LINE(tests);
-- OR
sql_stmt := 'select ' || COLS_LIKE('%E%', 'table') || ' from table';
DBMS_OUTPUT.PUT_LINE(sql_stmt);
end;
The end goal would be something such as this
select COLS_LIKE('%E%', 'table') from table;
What modifications can I make to my function or how I am calling to so that this function can be applied correctly.

Answer 1

Why you'd want to do such a thing I've no idea but you could return an open cursor to PL/SQL fairly easily:
create or replace function cols_like (
PTable in varchar2
, PColumn in varchar2
) return sys_refcursor
l_cols varchar2(32767);
c_curs sys_refcursor;
begin
select listagg(column_name, ', ') within group (order by column_id)
into l_cols
from user_tab_cols
where table_name = upper(Ptable)
and column_name like '%' || upper(PColumn) || '%'
;
open c_curs for '
select ' || l_cols || '
from ' || Ptable;
return c_curs;
end;
/
Returning this to a standard SQL statement will be a lot more difficult, this is because in selecting this function you're only selecting one column's worth of data. You want to be able to select N columns, which means you need to start returning nested tables that have been dynamically created.
I'm sure it's possible; but, before you get anywhere close to starting to attempt to do this think about why you're doing it. Ask a question where you don't state your end goal but where you state what your actual problem is. Chances are there's a lot simpler solution.

Answer 2

I was also having same problem and found this, and it is working for me. I was just making comparison of mobile numbers from two tables and in one of the tables some numbers have 0 in start and some don't. Finally got solution and just added % in start:
a.number was having numbers, in some of them starting 0 was missing. and b.number was accurate.
b.number like CONCAT('%',a.number)