Add and DROP DEFAULT : Default « Constraints « PostgreSQL

1. PostgreSQL
2. Constraints
3. Default

Add and DROP DEFAULT

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=# -- 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=#
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=# ALTER TABLE books ALTER id DROP DEFAULT;
ALTER 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=# drop table books;
DROP TABLE
postgres=#
           
       

Related examples in the same category