TreeMap 升序|降序排列 import java.util.Comparator; import java.util.TreeMap; public class Main { public static void main(String[] args) { TreeMap<Integer,Integer> map1 = new TreeMap<Integer,Integer>(); //默认的TreeMap升序排列 TreeMap<Integer,Integer>
经常会忘记mysql中升序和降序用什么字符来表示,现在就做个笔记:升序排列asc,降序排列desc,举个例子,下面是按时间降序调用栏目的文章,也即是栏目最新文章 [e:loop={"select classid, classname, classpath from `[!db.pre!]enewsclass` where classid=275 order by classid desc limit 9 ",100,24,0}]<ul><li><a hre
原文:https://leetcode.com/problems/word-frequency/ Write a bash script to calculate the frequency of each word in a text file words.txt. For simplicity sake, you may assume: words.txt contains only lowercase characters and space ' ' characters. Each wo
select *from wsb limit 5;显示前5行 select *from students LIMIT (m,n) (其中m是指记录开始的index,从0开始,表示第一条记录n是指从第m+1条开始,取n条.select * from tablename limit 2,4即取出第3条至第6条,4条记录) +where 筛选条件 select *from wsb where salary>2000; select *from where age is null;(空字段