PostgreSQL/Table/Add Column
Содержание
Add a column
postgres=#
postgres=# -- Creating the books table
postgres=#
postgres=# CREATE TABLE books (
postgres(# id integer UNIQUE,
postgres(# title text NOT NULL,
postgres(# author_id integer,
postgres(# subject_id integer,
postgres(# CONSTRAINT books_id_pkey PRIMARY KEY (id));
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "books_id_pkey" for table "books"
CREATE TABLE
postgres=#
postgres=# \d books;
Table "public.books"
Column | Type | Modifiers
------------+---------+-----------
id | integer | not null
title | text | not null
author_id | integer |
subject_id | integer |
Indexes:
"books_id_pkey" PRIMARY KEY, btree (id)
postgres=#
postgres=# -- Adding a column
postgres=#
postgres=# ALTER TABLE books ADD publication date;
ALTER TABLE
postgres=#
postgres=#
postgres=# \d books;
Table "public.books"
Column | Type | Modifiers
-------------+---------+-----------
id | integer | not null
title | text | not null
author_id | integer |
subject_id | integer |
publication | date |
Indexes:
"books_id_pkey" PRIMARY KEY, btree (id)
postgres=#
postgres=# drop table books;
DROP TABLE
postgres=#
postgres=#
Add a new column with check option
postgres=#
postgres=# CREATE TABLE employee (
postgres(# ID int,
postgres(# name varchar(10),
postgres(# salary real,
postgres(# start_date date,
postgres(# city varchar(10),
postgres(# region char(1)
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (1, "Jason", 40420, "02/01/94", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (2, "Robert",14420, "01/02/95", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (3, "Celia", 24020, "12/03/96", "Toronto", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (4, "Linda", 40620, "11/04/97", "New York", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (5, "David", 80026, "10/05/98", "Vancouver","W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (6, "James", 70060, "09/06/99", "Toronto", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (7, "Alison",90620, "08/07/00", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (8, "Chris", 26020, "07/08/01", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (9, "Mary", 60020, "06/09/02", "Toronto", "W");
INSERT 0 1
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region
----+--------+--------+------------+-----------+--------
1 | Jason | 40420 | 1994-02-01 | New York | W
2 | Robert | 14420 | 1995-01-02 | Vancouver | N
3 | Celia | 24020 | 1996-12-03 | Toronto | W
4 | Linda | 40620 | 1997-11-04 | New York | N
5 | David | 80026 | 1998-10-05 | Vancouver | W
6 | James | 70060 | 1999-09-06 | Toronto | N
7 | Alison | 90620 | 2000-08-07 | New York | W
8 | Chris | 26020 | 2001-07-08 | Vancouver | N
9 | Mary | 60020 | 2002-06-09 | Toronto | W
(9 rows)
postgres=#
postgres=#
postgres=# ALTER TABLE employee ADD COLUMN description text CHECK (description <> "");
ALTER TABLE
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region | description
----+--------+--------+------------+-----------+--------+-------------
1 | Jason | 40420 | 1994-02-01 | New York | W |
2 | Robert | 14420 | 1995-01-02 | Vancouver | N |
3 | Celia | 24020 | 1996-12-03 | Toronto | W |
4 | Linda | 40620 | 1997-11-04 | New York | N |
5 | David | 80026 | 1998-10-05 | Vancouver | W |
6 | James | 70060 | 1999-09-06 | Toronto | N |
7 | Alison | 90620 | 2000-08-07 | New York | W |
8 | Chris | 26020 | 2001-07-08 | Vancouver | N |
9 | Mary | 60020 | 2002-06-09 | Toronto | W |
(9 rows)
postgres=#
postgres=# \d employee;
Table "public.employee"
Column | Type | Modifiers
-------------+-----------------------+-----------
id | integer |
name | character varying(10) |
salary | real |
start_date | date |
city | character varying(10) |
region | character(1) |
description | text |
Check constraints:
"employee_description_check" CHECK (description <> ""::text)
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#
postgres=#
Adds a text column
postgres=# CREATE TABLE employee (
postgres(# ID int,
postgres(# name varchar(10),
postgres(# salary real,
postgres(# start_date date,
postgres(# city varchar(10),
postgres(# region char(1)
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (1, "Jason", 40420, "02/01/94", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (2, "Robert",14420, "01/02/95", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (3, "Celia", 24020, "12/03/96", "Toronto", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (4, "Linda", 40620, "11/04/97", "New York", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (5, "David", 80026, "10/05/98", "Vancouver","W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (6, "James", 70060, "09/06/99", "Toronto", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (7, "Alison",90620, "08/07/00", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (8, "Chris", 26020, "07/08/01", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (9, "Mary", 60020, "06/09/02", "Toronto", "W");
INSERT 0 1
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region
----+--------+--------+------------+-----------+--------
1 | Jason | 40420 | 1994-02-01 | New York | W
2 | Robert | 14420 | 1995-01-02 | Vancouver | N
3 | Celia | 24020 | 1996-12-03 | Toronto | W
4 | Linda | 40620 | 1997-11-04 | New York | N
5 | David | 80026 | 1998-10-05 | Vancouver | W
6 | James | 70060 | 1999-09-06 | Toronto | N
7 | Alison | 90620 | 2000-08-07 | New York | W
8 | Chris | 26020 | 2001-07-08 | Vancouver | N
9 | Mary | 60020 | 2002-06-09 | Toronto | W
(9 rows)
postgres=#
postgres=# -- Adds a text column
postgres=# ALTER TABLE employee ADD COLUMN address text;
ALTER TABLE
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region | address
----+--------+--------+------------+-----------+--------+---------
1 | Jason | 40420 | 1994-02-01 | New York | W |
2 | Robert | 14420 | 1995-01-02 | Vancouver | N |
3 | Celia | 24020 | 1996-12-03 | Toronto | W |
4 | Linda | 40620 | 1997-11-04 | New York | N |
5 | David | 80026 | 1998-10-05 | Vancouver | W |
6 | James | 70060 | 1999-09-06 | Toronto | N |
7 | Alison | 90620 | 2000-08-07 | New York | W |
8 | Chris | 26020 | 2001-07-08 | Vancouver | N |
9 | Mary | 60020 | 2002-06-09 | Toronto | W |
(9 rows)
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#
postgres=#
Altering column defaults
postgres=#
postgres=# -- Creating the books table
postgres=#
postgres=# CREATE TABLE books (
postgres(# id integer UNIQUE,
postgres(# title text NOT NULL,
postgres(# author_id integer,
postgres(# subject_id integer,
postgres(# CONSTRAINT books_id_pkey PRIMARY KEY (id));
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "books_id_pkey" for table "books"
CREATE TABLE
postgres=#
postgres=# \d books;
Table "public.books"
Column | Type | Modifiers
------------+---------+-----------
id | integer | not null
title | text | not null
author_id | integer |
subject_id | integer |
Indexes:
"books_id_pkey" PRIMARY KEY, btree (id)
postgres=#
postgres=#
postgres=# -- Altering column defaults
postgres=#
postgres=# ALTER TABLE books ALTER COLUMN id SET DEFAULT nextval("book_ids");
ERROR: relation "book_ids" does not exist
postgres=#
postgres=# \d books;
Table "public.books"
Column | Type | Modifiers
------------+---------+-----------
id | integer | not null
title | text | not null
author_id | integer |
subject_id | integer |
Indexes:
"books_id_pkey" PRIMARY KEY, btree (id)
postgres=#
postgres=# drop table books;
DROP TABLE
postgres=#
ALTER TABLE employee ADD COLUMN description text
postgres=#
postgres=# CREATE TABLE employee (
postgres(# ID int,
postgres(# name varchar(10),
postgres(# salary real,
postgres(# start_date date,
postgres(# city varchar(10),
postgres(# region char(1)
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (1, "Jason", 40420, "02/01/94", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (2, "Robert",14420, "01/02/95", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (3, "Celia", 24020, "12/03/96", "Toronto", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (4, "Linda", 40620, "11/04/97", "New York", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (5, "David", 80026, "10/05/98", "Vancouver","W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (6, "James", 70060, "09/06/99", "Toronto", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (7, "Alison",90620, "08/07/00", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (8, "Chris", 26020, "07/08/01", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (9, "Mary", 60020, "06/09/02", "Toronto", "W");
INSERT 0 1
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region
----+--------+--------+------------+-----------+--------
1 | Jason | 40420 | 1994-02-01 | New York | W
2 | Robert | 14420 | 1995-01-02 | Vancouver | N
3 | Celia | 24020 | 1996-12-03 | Toronto | W
4 | Linda | 40620 | 1997-11-04 | New York | N
5 | David | 80026 | 1998-10-05 | Vancouver | W
6 | James | 70060 | 1999-09-06 | Toronto | N
7 | Alison | 90620 | 2000-08-07 | New York | W
8 | Chris | 26020 | 2001-07-08 | Vancouver | N
9 | Mary | 60020 | 2002-06-09 | Toronto | W
(9 rows)
postgres=#
postgres=# ALTER TABLE employee ADD COLUMN description text;
ALTER TABLE
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region | description
----+--------+--------+------------+-----------+--------+-------------
1 | Jason | 40420 | 1994-02-01 | New York | W |
2 | Robert | 14420 | 1995-01-02 | Vancouver | N |
3 | Celia | 24020 | 1996-12-03 | Toronto | W |
4 | Linda | 40620 | 1997-11-04 | New York | N |
5 | David | 80026 | 1998-10-05 | Vancouver | W |
6 | James | 70060 | 1999-09-06 | Toronto | N |
7 | Alison | 90620 | 2000-08-07 | New York | W |
8 | Chris | 26020 | 2001-07-08 | Vancouver | N |
9 | Mary | 60020 | 2002-06-09 | Toronto | W |
(9 rows)
postgres=#
postgres=# \d employee;
Table "public.employee"
Column | Type | Modifiers
-------------+-----------------------+-----------
id | integer |
name | character varying(10) |
salary | real |
start_date | date |
city | character varying(10) |
region | character(1) |
description | text |
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#
postgres=#