要用动态SQL，拼接SQL。比如：
v_sql:=‘select a,b,’||v_table_column||’ from '||v_table_name;
execute immediate v_sql;

但你这里是for j in ,所以，也要改。需要对该行及其下的整段代码做动态处理。

另外，也可以考虑对这个部分再做一个存储过程（或函数），v_table_name和v_table_column做为入参。

1. for i in (select table_name,table_column from XXX) loop
2. v_table_name := i.table_name;
3. v_table_column := i.table_column;
4. for j in (select a,b,v_table_column from v_table_name) loop
5. ...
6. end loop;
7. end loop;

这个肯定涉及到了动态sql，但是和一般的动态sql有点区别，这里的动态sql字符串，需要作为一个游标，可以参考下面这个例子

declare
  l_sql varchar2(4000) := 'select * from dba_VIEWS a where a.VIEW_name IN (''DBA_TABLES'',''DBA_VIEWS'',''DBA_TAB_COLS'') ';
  l_row dba_VIEWS%rowtype;
  type r is record(
    a number,
    b number,
    c varchar2(200));
  l_row2 r;
  type cur is ref cursor;
  curs   cur;
  curs_2 cur;
begin
  open curs for l_sql;
  loop
    fetch curs
      into l_row;
    exit when curs%notfound;
  
    open curs_2 for 'select 1 a,2 b,'''||l_row.VIEW_name||''' from ' || l_row.VIEW_name||' WHERE ROWNUM<=5';
    loop
      fetch curs_2
        into l_row2;
      exit when curs_2%notfound;
    
      dbms_output.put_line(l_row2.a||','||l_row2.b||','||l_row2.c);
    
    end loop;
    close curs_2;
  end loop;
  close curs;
end;