delete from 表名 where id not in (select d.id from (SELECT id FROM 表名 GROUP BY c1,c2,c3,c4)as d) #去重复,把url重复,且区为空的中去掉.select * from TABLE where url in (select u.url from (select * from TABLE where id not in (select d.id from (SELECT id FROM TABLE GROUP
数据源 user name age 小红 18 小明 18 小芳 19 ------------------------------------------------------------------------------------------ – 默认逗号连接select u.age,group_concat(u.name) as NameStr from user u group by u.age; 预览: age NameStr 18 小红,小明 19 小
Given a non-negative integer num represented as a string, remove k digits from the number so that the new number is the smallest possible. Note: The length of num is less than 10002 and will be ≥ k. The given num does not contain any leading zero. Ex
写出将字符串中的数字转换为整型的方法,如:"as31d2v"->312,并写出相应的单元测试,输入超过int范围时提示不合法输入. public struct ConvertResult { public ConvertState State; public int Number; } public enum ConvertState { // 输入不合法 InValid = , // 输入合法 Valid = } public class StringHelper { publ
SELECT oam.id , GROUP_CONCAT(oacm.name) category FROM om_article_manage oam LEFT JOIN om_article_category_relation oacr ON oacr.article_id = oam.id LEFT JOIN om_article_category_manage oacm ON oacm.id = oacr.category_id GROUP BY oam.id ORDER BY oacm.
今天在codewar做练习题时,要求写一个函数把一个字符串去掉WUB这些多余的字符然后把剩下的组成一句话输出,如传入"WUBAWUBBWUBCWUB"后返回"A B C"我的源代码是如下 function songDecoder(song){ // ... var words=song.split('WUB'); var str1=""; for(var i=0;i<words.length;i++){ if(words[i]=="