复合类型定义：
postgres=# create type complex as(r double precision,i double precision);
CREATE TYPE
postgres=# create type persion as(name text,age int,sex boolean);
CREATE TYPE
postgres=#
使用复合类型创建表：
postgres=# create table testfh(id complex,people persion);
CREATE TABLE
postgres=#

postgres=# insert into testfh values ((1,2),('李明','27','1'));
INSERT 0 1
postgres=# select * from testfh;
  id   |   people   
-------+-------------
 (1,2) | (李明,27,t)
(1 row)

postgres=# select (people).name from testfh;
 name
------
 李明
(1 row)
postgres=# update testfh set people.name='李大明';
UPDATE 1
postgres=# select (people).name from testfh;
  name 
--------
 李大明
(1 row)

postgres=#