select from_unixtime(lasttalktime),lasttalktime from im_ims_friend
select unix_timestamp('2013-10-13')
select count(*) from im_ims_friend where lasttalktime>unix_timestamp('2013-10-13')
select count(*) from im_ims_friend_copy where lasttalktime>unix_timestamp('2013-10-28') and userid=6736359
INSERT INTO im_ims_friend SELECT * FROM im_ims_friend_copy where lasttalktime>unix_timestamp('2013-10-20')
select unix_timestamp('2013-10-13')
select count(*) from im_ims_friend where lasttalktime>unix_timestamp('2013-10-13')
select count(*) from im_ims_friend_copy where lasttalktime>unix_timestamp('2013-10-28') and userid=6736359
INSERT INTO im_ims_friend SELECT * FROM im_ims_friend_copy where lasttalktime>unix_timestamp('2013-10-20')
delete FROM im_ims_friend where lasttalktime>unix_timestamp('2013-10-20') and lasttalktime<unix_timestamp('2013-10-23')
select from_unixtime(1210003200) datetime
本文深入探讨了SQL查询技术,包括如何从特定时间点获取数据、数据计数、筛选和更新数据库记录,以及批量数据操作。同时,介绍了数据安全管理和数据库备份策略。
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