mysql 找出重复数据

发表于2016-07-30|更新于2026-10-28|mysql

1	SELECT * , count(openid) as count FROM `cul_logindata` GROUP BY `openid` HAVING count>1

文章作者: developer

文章链接: https://blog.iguojin.com/2016/07/30/mysql%20%E6%89%BE%E5%87%BA%E9%87%8D%E5%A4%8D%E6%95%B0%E6%8D%AE/

版权声明: 本博客所有文章除特别声明外，均采用 CC BY-NC-SA 4.0 许可协议。转载请注明来源 Dev！

mysql 找出重复数据

相关推荐

redis mysql 性能记录读写速度 windows linux

thinkphp5.0.10运行时间记录 centos7.2 腾讯云 1核1G 高效云盘逐个写入redis lpush 100000条 3.381005smysql insert 100000条 23.706291s 获取最后redis rpop 0.001823smysql order|limit 0.003046s 索引查找redis lindex 0.001536smysql id 0.002653S windows10 2核4G SSD 逐个写入redis lpush 10000 12.013191smysql insert 10000 41.127062s 获取最后redis rpop 0.054366smysql order|limit 0.066480s 索引查找redis lindex 0.054666smysql id 0.069864s

mysql 5.5 修改 root 密码

启动数据库1mysqld --skip-grant-tables 更新密码12use mysql;UPDATE user SET Password=PASSWORD('root') where USER='root';

mysql 数据库升级

本机把mysql5.5升级到mysql8.0记录备份数据在mysql5.5执行mysqldump 1mysqldump -u root -pPASSWORD --all-databases > ./all.sql 停止mysql5 安装mysql8,导入数据 12mysql -uroot -p rootsource ./all.sql 启动mysql8 升级不兼容表 1mysql_upgrade -u root -p

mysql laragon 启动报错

更换laragon的mysql版本后突然出现如下错误 1Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist 解决方法将下载的mysql5.5目录里自带的data文件夹复制到laragon的data文件夹里

mysql 统计重复记录数量

123456SELECT COUNT(*) as total FROM ( SELECT count(openid) as t FROM user GROUP BY `openid` HAVING t > 1 limit 1000) as a 如果下面写法会很慢 123456SELECT COUNT(*) as total FROM form_user WHERE id IN( SELECT count(id) FROM form_user GROUP BY `openid` HAVING COUNT(openid) > 1 limit 1000)

mysql max min 必须放在-条件之后

1SELECT *,max(marks) FROM `form_log` where reason = 'astrazeneca' group by userid

数据加载中