postgresql 表结构变更相关操作

1、列操作

新增一列：alter table [tbl_name] add column [column_name] [type]

删除一列：alter table [tbl_name] drop [column_name];

修改列名：alter table [tbl_name] rename [column_name] to [column_name_1]; 

修改列类型：alter table [tbl_name] alter COLUMN [column_name] type varchar(255)

2、序列操作

重置序列：alter sequence xxx restart with 1

创建序列：create sequence xxx START with 1 INCREMENT by 1 NO MINVALUE NO MAXVALUE CACHE 1

给某一列赋上序列：alter table [tbl_name] alter column [column_name] set default nextval('xxx')

3、设置主键约束

alter table [tbl_name] add constraint pkey_name primary key(id);

 4、去掉主键和非空约束

alter table [tbl_name] drop constraint pkey_name;
alter table [tbl_name] alter [col_name] drop not null;