Another attempt to create "on the fly" condition in PL/SQL

Question

Here is the code:
---BEGIN ----
declare
my_var_list VARCHAR2(4000);
cursor my_curr is select aa.column_name as my_col_name from user_tab_columns aa, user_tab_columns bb
where aa.column_name = bb.column_name
and aa.table_name = 'MY_SUBSET_TABLE' and bb.table_name = 'MY_SUPERSET_TABLE';
begin
for my_ind in my_curr loop
my_var_list := my_var_list || my_i.my_col_name || ', ';
end loop;
insert into MY_SUPERSET_TABLE (my_var_list) select my_var_list from MY_SUBSET_TABLE;
end;
run;
---END---
I plan to extract column name from user_tab_column, and concat it into a variable "my_var_list".
The question now is, given the my_var_list contain column names (separate by comma), how can I use it in the select statement below?
insert into MY_SUPERSET_TABLE (my_var_list) select my_var_list from MY_SUBSET_TABLE;
Any idea on how to improve this script? I am running on Oracle9i ... using SQL Dev.
Thanks much...

Answer 1

It's a terrible idea, but it can be done. It could leave you open for sql injection hacks:
declare
my_sql VARCHAR2(4000);
column_list varchar2(4000);
v_iteration number := 0;
begin
for i in ( select column_name from user_tab_columns where table_name = 'T1') loop
if v_iteration = 0 then
column_list := i.column_name;
else
column_list := column_list||','||i.column_name;
end if;
v_iteration := v_iteration + 1;
end loop;
execute immediate 'insert into t2('||column_list||') select '||column_list||' from t1';
end;
/