Cannot drop a column in PostgreSQL

Question

I am pretty new in PostgreSQL and only know basic operations about database. I have a database called neuro_db with username neuro_user. Now I found I cannot delete a column in a table from neuro_db.

After I tried psql neuro_db in ubuntu 14.04, I got in a command line started with neuro_db=#. The \d command would show a table like this:

                         List of relations
 Schema |               Name                |   Type   |   Owner
--------+-----------------------------------+----------+------------
 public | auth_group                        | table    | neuro_user
 public | auth_group_id_seq                 | sequence | neuro_user
 public | auth_group_permissions            | table    | neuro_user
 public | auth_group_permissions_id_seq     | sequence | neuro_user
 public | auth_permission                   | table    | neuro_user
 public | auth_permission_id_seq            | sequence | neuro_user
 public | auth_user                         | table    | neuro_user
 public | auth_user_groups                  | table    | neuro_user
 public | auth_user_groups_id_seq           | sequence | neuro_user
 public | auth_user_id_seq                  | sequence | neuro_user
 public | auth_user_user_permissions        | table    | neuro_user
 public | auth_user_user_permissions_id_seq | sequence | neuro_user
 public | django_admin_log                  | table    | neuro_user
 public | django_admin_log_id_seq           | sequence | neuro_user
 public | django_content_type               | table    | neuro_user
 public | django_content_type_id_seq        | sequence | neuro_user
 public | django_migrations                 | table    | neuro_user
 public | django_migrations_id_seq          | sequence | neuro_user
 public | django_session                    | table    | neuro_user
 public | neuro_category                    | table    | neuro_user
 public | neuro_category_id_seq             | sequence | neuro_user
 public | neuro_page                        | table    | neuro_user
 public | neuro_page_id_seq                 | sequence | neuro_user
(23 rows)

I wanted to edit the table "neuro_page" and after typing \d neuro_page , it will show this table:

                                   Table "public.neuro_page"
   Column    |          Type          |                        Modifiers
-------------+------------------------+---------------------------------------------------------
 id          | integer                | not null default      nextval('neuro_page_id_seq'::regclass)
 category_id | integer                | not null
 title       | character varying(128) | not null
 text        | text                   | not null
 url         | character varying(200) | not null
 photo       | character varying(100) | not null
 order       | character varying(128) | not null
 date        | date                   | not null
 views       | integer                | not null
 likes       | integer                | not null

I wanted to delete the "order" column in this table so I tried typed ALTER TABLE neuro_page DROP COLUMN order right after the neuro_db=# line, but nothing happened. There was also nothing after trying ALTER TABLE neuro_page and DROP COLUMN order respectively. The "order" column is still there! And no error information!

I have also searched on google for the answer but found nothing. I think I have followed the normal operations in database but can not drop a single column in a table. There is no foreign key for "order" column.

I'd be very greatful if anyone can help me with this issue. Thanks!

Answer 1

You need to escape the column name order in backticks because order is a keyword (e.g. order by 'column_name'). Make sure you are using a semicolon to show the end of the command:

ALTER TABLE neuro_page DROP COLUMN `order`;