sql - pg: left join on table puts nil records first -

here project table:

 column   |            type             |                       modifiers                       | storage  | stats target | description  ------------+-----------------------------+-------------------------------------------------------+----------+--------------+-------------  id         | integer                     | not null default nextval('projects_id_seq'::regclass) | plain    |              |   name       | character varying(255)      |                                                       | extended |              |   repo_id    | integer                     |                                                       | plain    |              |   created_at | timestamp without time zone |                                                       | plain    |              |   updated_at | timestamp without time zone |                                                       | plain    |              |   user_id    | integer                     |                                                       | plain    |              |   data_path  | character varying(255)      |                                                       | extended |              |   private    | boolean                     | default false                                         | plain    |              |   uniqueurl  | character varying(255)      |                                                       | extended |              |   urlbase    | character varying(255)      |                                                       | extended |              |   ancestry   | character varying(255)      |                                                       | extended |              |   deleted_at | timestamp without time zone |                                                       | plain    |              |  indexes:     "projects_pkey" primary key, btree (id)     "index_projects_on_name_and_user_id" unique, btree (name, user_id)     "index_projects_on_ancestry" btree (ancestry)     "index_projects_on_deleted_at" btree (deleted_at) has oids: no 

and here rating_cache table:

 column     |            type             |                         modifiers                          | storage  | stats target | description  ----------------+-----------------------------+------------------------------------------------------------+----------+--------------+-------------  id             | integer                     | not null default nextval('rating_caches_id_seq'::regclass) | plain    |              |   cacheable_id   | integer                     |                                                            | plain    |              |   cacheable_type | character varying(255)      |                                                            | extended |              |   avg            | double precision            | not null                                                   | plain    |              |   qty            | integer                     | not null                                                   | plain    |              |   dimension      | character varying(255)      |                                                            | extended |              |   created_at     | timestamp without time zone |                                                            | plain    |              |   updated_at     | timestamp without time zone |                                                            | plain    |              |  indexes:     "rating_caches_pkey" primary key, btree (id)     "index_rating_caches_on_cacheable_id_and_cacheable_type" btree (cacheable_id, cacheable_type) has oids: no 

i doing left outer join on 2 tables with:

select  "projects".* "projects" left outer join rating_caches on rating_caches.cacheable_id = projects.id  "projects"."deleted_at" null  order rating_caches.avg desc 

this orders projects correctly (highest avg come first) projects no matching record in rating_caches table come before highest avg. ex: projects:

id  name 1   2   b 3   c 

rating_caches:

id cacheable_id avg 1  3            3.0 2  2            2.5 

result of query looks like:

id name 1  3  c 2  b 

shouldn't project id = 1 come last?

just use nulls last:

order rating_caches.avg desc nulls last 

as note, documentation specifies:

the nulls first , nulls last options can used determine whether nulls appear before or after non-null values in sort ordering. default, null values sort if larger non-null value; is, nulls first default desc order, , nulls last otherwise.