写动态sql，下面是删表的例子
一:
一:
spool droptable.sql
select 'drop table '||table_name||';' from user_tables;
spool off
start droptable.sql
二:
create or replace procedure pro_droptable is
cursor cur is select table_name from user_tables;
drop_sql varchar2(1000);
begin
for tbname in cur loop
begin
drop_sql:='drop table '||tbname.table_name;
execute immediate drop_sql;
end;
end loop;
end pro_droptable;
