SQL高级助手

1: 列出所有数据 select * from pi_data
2: 删除所有数据 delete from pi_data
3: 列出某一栏目数据 select * from pi_data where tid =(select tid from pi_type where tname = '频道1')
4: 删除某一栏目数据 delete from pi_data where tid =(select tid from pi_type where tname = '频道1')
5: 列出某一专题的数据 select * from pi_data where v_topic =(select id from pi_topic where name = '男人必看十部')
6: 删除 某一专题的数据 delete from pi_data where v_topic =(select id from pi_topic where name = '男人必看十部')
(请谨慎操作,以免造成数据错误![?])