alter table tabelname add new_field_id int(5) unsigned default 0 not null auto_increment ,add primary key (new_field_id); //增加一个新列 alter table t2 add d timestamp; alter table infos add ex tinyint not null default '0'; //删除列 alter table t2 drop column c; //重命名列 alter table t1 change a b integer; //改变列的类型 alter table t1 change b b bigint not null; alter table infos change list list tinyint not null default '0'; //重命名表 alter table t1 rename t2; //加索引 alter table tablename change depno depno int(5) not null; alter table tablename add index 索引名 (字段名1[,字段名2 …]); alter table tablename add index emp_name (name); //加主关键字的索引 alter table tablename add primary key(id); //加唯一限制条件的索引 alter table tablename add unique emp_name2(cardnumber); //删除某个索引 alter table tablename drop index emp_name; //修改表: //增加字段: ALTER TABLE table_name ADD field_name field_type; //修改原字段名称及类型: ALTER TABLE table_name CHANGE old_field_name new_field_name field_type; //删除字段: ALTER TABLE table_name DROP field_name; 转载请保留固定链接: https://linuxeye.com/database/1014.html |