desc tablename;
describe tablename; 2.show命令
show columns from tablename;
show create table tablename 3.select命令(SQL语句)
#查看表中所有列的信息
use information_schema;
select column_name from columns where table_name='table_name';
#查看所有列的信息
select column_name from columns where table_name='table_name';