抽样误差的来源主要有抽样的随机性和

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='30773' and id < 2477784 and id<>'2477784' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='30773' and id > 2477784 and id<>'2477784' order by id asc limit 5