fenyu8的专栏

UPDATE test_area_country t SET t.country_code =( SELECT country_code FROM ( SELECT * FROM test_country ) t1 WHERE t.country_name = t1.country_name );

/*查询重复数据*/SELECT * FROM index_price WHERE ( fund_number, date ) IN ( SELECT fund_number, date FROM index_price GROUP BY fund_number, date HAVING count(*)> 1 ) ORDER BY fund_number, date DESC; /*删除重复数据，一次只删除每组重复数据中的一条数据，若一组数据多次重复，要执行多次*/ D.

1.拉取镜像docker pull nacos/nacos-server2.挂载目录mkdir -p /var/apps/nacos/logs/ #新建logs目录3.启动容器docker run -d \-e MODE=standalone \-e PREFER_HOST_MODE=hostname \-e SPRING_DATASOURCE_PLATFORM=mysql \-e MYSQL_SERVICE_HOST=127.0.

MySQL生成序列号方法一：set @num = 0;select @num:=@num+1 as num,temp.* from jj_product_info as temp;方法二：select (@i:=@i+1) as i,a.* from jj_product_info as a,(select @i:=0) as it获取上一行或下一行select t.*,t1.price price1from(select (@i:=@i+1) as i,a.* fro..

服务器环境是centos 7.5 这篇教程是通过yum方式安装的。1.centos下彻底删除MYSQL1.1 删除Mysql yum remove mysql mysql-server mysql-libs mysql-server; find / -name mysql 将找到的相关东西delete掉(rm -rf /var/lib/mysql)； rpm -qa|grep mysql(查询出来的东东yum remove掉) rm /etc/my.cnf...