PG DDL 常用语法

增加字段

alter table test add column_name int;
alter table task  add testname varchar(32) not null;

修改字段名称

alter table test rename column status to status1;

修改字段类型，隐式转换

alter table task alter column cusid type varchar(32) ;

修改字段类型，显式转换

alter table task alter column customerid type int using customerid::int;

删除字段

alter table task drop column testid;

去除 not null

alter table task alter column remark drop not null;

设置 not null

alter table test alter column remark set not null;

设置默认值

alter table cus alter column xzqh set default 0;

创建表

create table test
(
  id integer not null
    constraint test_pkey
      primary key,
  testid integer not null,
  tasktype smallint not null,
  status smallint not null,
  remark varchar(500) not null,
  createtime timestamp not null
);

comment on table task is '任务';
comment on column test.tasktype is '注释';
alter table test owner to usertest;