直接上代码:
1、先创建一个表:
1 create table user( 2 uid integer not null, 3 username character varying(50) NOT NULL, 4 email character varying(100), 5 tel character varying(50) 6 7 )
2、然后发现需要将uid 类型修改为序列类型,但是postgreql不支持将integer修改为serial,曲线救国做法如下:
--新建一个字段uid1 alter table user add column uid1 serial; --删除老字段uid alter table user drop column uid; --修改uid1字段名称为uid alter table user rename uid1 to uid; --增加主键 alter table user add primary key (uid);