com.swift.jztk.biz;import java.util.Collections; import java.util.Comparator; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Random;import com.google.gson.Gson; import com.swift.jztk.bean.Result; import com.swift.jztk.bean.Root; import com.swift.jztk.dao.IQuestionDao; import com.swift.jztk.dao.QuestionDaoImpl;public class QuestionBizImpl implements IQu...
FUNCTION IF EXISTS rand_string; DELIMITER $$ CREATE FUNCTION rand_string(n INT) RETURNS VARCHAR(255) BEGINDECLARE chars_str varchar(100) DEFAULT ‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789‘;DECLARE return_str varchar(255) DEFAULT ‘‘;DECLARE i INT DEFAULT 0;WHILE i < n DOSET return_str = concat(return_str,substring(chars_str , FLOOR(1 + RAND()*62 ),1));SET i = i +1;END WHILE...
网上看到一个python练习题，要随机生成8位数的优惠券，并希望能保存到mysql数据库中。自己查资料写了下面的一段代码完成这个小作业#!/usr/bin/env python # -*- coding: utf-8 -*- #author qingmiao import MySQLdb as mdb import sys import random,stringdef random_code(code_length,code_long): i=1 result = [] while i<=code_length: salt = .join(random.sample(string.ascii_letters + string.digits,...
sql语句有几种写法 1：SELECT * FROM tablename ORDER BY RAND() LIMIT 想要获取的数据条数； 2：SELECT *FROM `table` WHERE id >= (SELECT FLOOR( MAX(id) * RAND()) FROM `table` ) ORDER BY id LIMIT 想要获取的数据条数; 3：SELECT * FROM `table` AS t1 JOIN (SELECT ROUND(RAND() * (SELECT MAX(id) FROM `table`)) AS id) AS t2 WHERE t1.id >= t2.idORDER BY t1.id ASC LIMIT 想要获取的数据条数; 4：SELECT * FROM `tab...
SELECT * FROM tableName ORDER BY RAND() LIMIT n 数据量小的话还可以， 数据量大起来了， 就影响性能了。 根据表中的ID， 假设表中有1000条数据，那么先生成1-1000的随机数，比如放进数组中，然后遍历，然后where id = randnum，循环查询n次。想不到别的办法了。 mysql随机取出n条数据标签：循环 sel order 查询 HERE rand 随机数 from 数据 本文系统来源：https://www.cnblogs.com/bneglect/p/113242...
语句一：select * from users order by rand() LIMIT 1MYSQL手册里面针对RAND()的提示大概意思就是，在 ORDER BY从句里面不能使用RAND()函数，因为这样会导致数据列被多次扫描，导致效率相当相当的低，效率不行，切忌使用。语句二：SELECT * FROM users AS t1 JOIN (SELECT ROUND(RAND() * ((SELECT MAX(userId) FROM `users`)-(SELECT MIN(userId) FROM users))+(SELECT MIN(userId) FROM users)) AS userId) AS t2 WHERE t1.user...
2. 添加配置原件-jdbc connection config 3. 添加jdbc请求 填写信息 4. 连接数据库 OK 5. 增加语句：jdbc requests 配置信息如下 查看 DebugSample： 6. 修改登录接口 username 查看结果： 7. 获取所有值 ${userNames_#} 查看结果：8. 函数助手 ${__Random(1,${userNames_#},)} ${__Random(1, ${userNames_#},)} 表示随机生成1~6的值 替换DebugSample_${userNames_#} 运行查看结果、并没有发现发现输出 ...
慢 SELECT * FROM table_name ORDER BY rand() LIMIT 5;-- 较慢 SELECT * FROM `table` WHERE id >= (SELECT floor( RAND() * ((SELECT MAX(id) FROM `table`)-(SELECT MIN(id) FROM `table`)) + (SELECT MIN(id) FROM `table`))) ORDER BY id LIMIT 1;-- 快 `table 有 id 字段 SELECT * FROM `table` AS t1 JOIN (SELECT ROUND(RAND() * ((SELECT MAX(id) FROM `table`)-(SELECT MIN(id) FROM `table`))+(SELECT MIN(id) FROM `t...
UUID(); -- 37747019-90a2-11e9-9806-00505683703f我们可以配合REPLACE()函数替换掉【-】符号来生成32位的不带【-】符号的随机ID。SELECT REPLACE(UUID(), ‘-‘, ‘‘); -- 62d1556390a211e9980600505683703f我们也可以配合UPPER()函数将小写字母转换为大写。SELECT UPPER(REPLACE(UUID(), ‘-‘, ‘‘)); -- C59ED7B190A211E9980600505683703F在做数据导入的时候经常会用上。 "我们有时候想要对别人好，但是在这之前先想想别人...
create table test01 ( id1 int not null auto_increment, name varchar(30), primary key(id1) );create table test02 ( id2 int not null auto_increment, name varchar(30), primary key(id2) ); （2）创建存储过程CREATE DEFINER=`root`@`%` PROCEDURE `p_insert`() BEGIN #Routine body goes here... DECLARE str1 varchar(30); DECLARE str2 varchar(30); DECLARE i int; set i = 0;while i < 10000 do set str1 = substrin...
1 begin2 declare i int;3 set i=0;4 while i<1000 do5 insert INTO TEST(name,week,hash_code,model,config,province,city,end_update_time,buy_end_time,create_time,update_time,code)6 values((SELECT CONCAT(‘TES‘,CEILING(RAND()*90000000000000+10000000000000))),7 "2020-04-23 17:44:01","20200424132946","测试","EESS1P","上海","上海","2020-04-23 17:44:01","2020-04-23 17:44:01","2020...
, 100 方案三：mysql实现(利用数据更新字段实现) SELECT * FROM `sd_crowd_label_enum` order by gmt_create LIMIT 0, 100 每次操作完，数据更新字段时间都会更新 参考： https://www.cnblogs.com/jackhub/p/3804358.html从MySQL随机选取数据方案标签：and mysq sel limit 方案 set -- blog new 本文系统来源：https://www.cnblogs.com/guihong/p/12870640.html
ID连续的情况下（注意不能带where，否则结果不好）： SELECT *FROM `mm_account` AS t1 JOIN (SELECT ROUND(RAND() * (SELECT MAX(id) FROM `mm_account`)) AS id) AS t2WHERE t1.id >= t2.idORDER BY t1.id ASC LIMIT 4;ID不连续的情况下： SELECT * FROM `mm_account` WHERE id >= (SELECT floor(RAND() * (SELECT MAX(id) FROM `mm_account`))) and city="city_91" and showSex=1ORDER BY id LIMIT 4; 假设你的表叫做mm_accoun...
* FROM country ORDER BY RAND() LIMIT 3;使用：ORDER BY RAND()mysql--随机获取一张表里的数据行；标签：数据 col rand limit sel code mysql str order 本文系统来源：https://www.cnblogs.com/lishidefengchen/p/13296604.html
random from random import choice as choice import mysql.connector import string def Create_Name():first_name = [‘赵‘,"钱","孙","李","王","林"]second_name = ["林","明","群","威","庆","月"]last_name = [‘群‘,"宁","国","龙","丹","昊"]name = choice(first_name)+choice(second_name)+choice(last_name)return name.rstrip() def Create_class():Class = ‘0123456‘ Class_name = ‘三年‘+choice(Class)+‘班‘r...