declare
cursor tablename is select distinct table_name from user_tab_columns;
names varchar2(60);
cursor columnname is select column_name from user_tab_columns where
table_name=names;
counter number;
counters number;
begin
for r_table in tablename
loop
names:=r_table.table_name;
DBMS_output.put(r_table.table_name || '(');
counter:=0;
select count(*)   into counters  from user_tab_columns where table_name=r_table.table_name ;
for r_columns in columnname
loop

counter:=counter +1;
if counters -1 =counter

then
dbms_output.put(r_columns.column_name|| ')');
else
dbms_output.put(r_columns.column_name||',');
end if;
exit when columnname%notfound;
end loop;
DBMS_OUTPUT.new_line;
exit when tablename%rowcount=4;
end loop;
end;