福哥答案2020-07-06:表a和表b的字段都是id和tid,数据类型都是int.查询结果顺序上以 表a 为准.1.JOIN.SELECT * FROM a JOIN b ON a.tid = b.tid LIMIT 200 OFFSET 500002.子查询.SELECT * FROM (SELECT ROW_NUMBER() OVER (ORDER BY T.tid) AS num, T.*FROM(SELECT a.id AS aid,a.tid,b.id AS bidFROM b JO…
1.如果A表TID是自增长,并且是连续的,B表的ID为索引 select * from a,b where a.tid = b.id and a.tid>500000 limit 200; 2.如果A表的TID不是连续的,那么就需要使用覆盖索引.TID要么是主键,要么是辅助索引,B表ID也需要有索引. select * from b , (select tid from a limit 50000,200) a where b.id = a .tid;…
https://codedefault.com/2018/using-linq-to-get-the-last-n-elements-of-a-collection-in-csharp-application 方案一 collection.Skip(Math.Max(0, collection.Count() - N)); 我们也可以把它写成一个静态扩展方法,如: public static class MiscExtensions { public static IEnumerable<T>…