-- 表不存在 | |
create table tablename_backup as select * from tablename; | |
-- 表已存在 | |
truncate table tablename_backup; | |
insert into tablename_backup select * from tablename; | |
-- 数据从一张表转到另一张表 | |
insert into table1(username, password) select username, password from table2; |
