postgresql 修改表结构，添加索引

//添加一个表字段 testuser=> alter table test add sex integer; ALTER TABLE testuser=> \d test Table "public.test" Column | Type | Modifiers --------------+-----------------------+--------------------------------------------------- id | integer | not null default nextval('seq_test_id'::regclass) name | character varying(32) | date_created | date | sex | integer | Indexes: "testuser_id_pk" PRIMARY KEY,btree (id) //修改表字段类型 testuser=> alter table test alter sex type varchar(1); ALTER TABLE testuser=> \d test Table "public.test" Column | Type | Modifiers --------------+-----------------------+--------------------------------------------------- id | integer | not null default nextval('seq_test_id'::regclass) name | character varying(32) | date_created | date | sex | character varying(1) | Indexes: "testuser_id_pk" PRIMARY KEY,btree (id) //创建唯一索引 testuser=> create unique index unique_name on test(name); CREATE INDEX testuser=> \d test Table "public.test" Column | Type | Modifiers --------------+-----------------------+--------------------------------------------------- id | integer | not null default nextval('seq_test_id'::regclass) name | character varying(32) | date_created | date | sex | character varying(1) | Indexes: "testuser_id_pk" PRIMARY KEY,btree (id) "unique_name" UNIQUE,btree (name) //表字段改名 testuser=> alter table test rename sex to age; ALTER TABLE testuser=> \d test Table "public.test" Column | Type | Modifiers --------------+-----------------------+--------------------------------------------------- id | integer | not null default nextval('seq_test_id'::regclass) name | character varying(32) | date_created | date | age | character varying(1) | Indexes: "testuser_id_pk" PRIMARY KEY,btree (name) //删除表字段 testuser=> alter table test drop age; ALTER TABLE