refactor: add type for all_m2o_and_o2o_rels

Author: steve-chavez

sql/pgrst_schema_cache.sql

@@ -4,8 +4,21 @@
 -- and pg doesn't allow it as a view column.
 create type ref_pair as (col text, ref text);
 
+create type relationship as (
+  table_schema         text,
+  table_name           text,
+  foreign_table_schema text,
+  foreign_table_name   text,
+  is_self              bool ,
+  constraint_name      text,
+  cols_and_fcols       ref_pair[],
+  is_one_to_one        bool
+);
+
 -- same query as PostgREST's allM2OandO2ORels
-create view all_m2o_and_o2o_rels as
+create function all_m2o_and_o2o_rels ()
+returns setof relationship as $$
+
 with
 pks_uniques_cols as (
   select
@@ -44,6 +57,8 @@ where traint.contype = 'f'
 and traint.conparentid = 0
 order by traint.conrelid, traint.conname;
 
+$$ language sql stable;
+
 
 -- type for the array of (column_name, view_columns[]), otherwise the creation of the function would fail
 CREATE TYPE col_dep AS (

test/expected/m2o_o2o.out

@@ -1,6 +1,6 @@
-select * from all_m2o_and_o2o_rels;
-   table_schema   |        table_name        | foreign_table_schema |  foreign_table_name  | is_self |                       constraint_name                       |                                     cols_and_fcols                                      | one_to_one 
-------------------+--------------------------+----------------------+----------------------+---------+-------------------------------------------------------------+-----------------------------------------------------------------------------------------+------------
+select * from all_m2o_and_o2o_rels();
+   table_schema   |        table_name        | foreign_table_schema |  foreign_table_name  | is_self |                       constraint_name                       |                                     cols_and_fcols                                      | is_one_to_one 
+------------------+--------------------------+----------------------+----------------------+---------+-------------------------------------------------------------+-----------------------------------------------------------------------------------------+---------------
  public           | public_orders            | public               | public_consumers     | f       | public_orders_consumer_fkey                                 | {"(consumer,id)"}                                                                       | f
  test             | has_fk                   | test                 | auto_incrementing_pk | f       | has_fk_fk_fkey                                              | {"(auto_inc_fk,id)"}                                                                    | f
  test             | has_fk                   | test                 | simple_pk            | f       | has_fk_simple_fk_fkey                                       | {"(simple_fk,k)"}                                                                       | f