泉水依然

1.增加一个字段(一列) alter table table_name add column column_name type default value;   type指该字段的类型,value指该字段的默认值 例如:alter table mybook add column publish_house varchar(10) default ''; 2.更改一个字段名字(也可以改变类型和...

创建用户，授权. create user lzquan identified by '123456'; grant all privileges on *.* to 'lzquan'@'localhost' identified by '123456'; flush privileges;   删除用户,收回权限 delete from mysql.u...

CREATE TABLE `tb_file_authorize` ( `authorize_id` int(11) NOT NULL auto_increment, `str_id` int(11) default NULL COMMENT '用户标识', `file_id` int(11) default NULL COMMENT '文件标识', `right_id` i...

  select c.cid from card as c where ( (select bid from book where bname='网络') in (select b.bid from borrow as b where b.cid=c.cid) ) and ( (select bid from book where bn...