test的博客

数据库二进制图片展示到网页上两种方式

create table table1 as select * from table2 这句是先创建一个表，再复制结构和数据。create table table1 select * from table2 这句是先创建一个表，再复制结构和数据。insert into table1 select * from table2 复制数据到新的表。insert into table1 select * from table2 复制数据到新的表。

方法一：SELECTSUBSTRING_INDEX(GROUP_CONCAT(id ORDER BY recording_time DESC),',',1) as id,SUBSTRING_INDEX(GROUP_CONCAT(happened_type ORDER BY recording_time DESC),',',1) as happened_type,SUBSTRING_INDEX(GROUP_CONCAT(happened_info ORDER BY recordi...