Mysql中返回一个数据库的所有表名,列名数据类型备注

desc 表名;
show columns from 表名;
describe 表名;
show create table 表名;use information_schema
select * from columns where table_name='表名';

顺便记下：
show databases;
也可以这样文章源自很文博客https://www.hinven.com很文博客-https://www.hinven.com/46495.html

use information_schema文章源自很文博客https://www.hinven.com很文博客-https://www.hinven.com/46495.html

select table_schema,table_name from tables where table_schema='数据库名'文章源自很文博客https://www.hinven.com很文博客-https://www.hinven.com/46495.html

use 数据库名;
show tables;
原有一unique索引AK_PAS_Name(PAC_Name)在表tb_webparamcounter中，
执行以下sql修改索引
alter table tb_webparamcounter drop index AK_PAS_Name;
alter table tb_webparamcounter add UNIQUE AK_PAS_Name(PC_ID,PAC_Name);文章源自很文博客https://www.hinven.com很文博客-https://www.hinven.com/46495.html

若发现索引的逻辑不对，还需要再加一个字段进去，执行
alter table tb_webparamcounter drop index AK_PAS_Name;
alter table tb_webparamcounter add UNIQUE AK_PAS_Name(PC_ID,PAC_Name,PAC_Value);
注意：这时的PC_ID,PAC_Name,PAC_Value三个字段不是FOREIGN KEY
否则必需先drop FOREIGN KEY，再重做上一步才行文章源自很文博客https://www.hinven.com很文博客-https://www.hinven.com/46495.html

获取列名数据类型备注
SELECT COLUMN_NAME, DATA_TYPE, COLUMN_COMMENT FROM information_schema.columns WHERE table_name = ?文章源自很文博客https://www.hinven.com很文博客-https://www.hinven.com/46495.html