refactor: make the function that queries all tables more reusable

- Merges postgrest_get_all_tables and postgrest_get_all_composite_types
- Removes the need of using unnest(), making the queries a bit more performant

Author: laurenceisla

sql/components.sql

@@ -17,40 +17,84 @@ $$;
 create or replace function oas_build_component_schemas(schemas text[])
 returns jsonb language sql stable as
 $$
-  select oas_build_component_schemas_from_tables(schemas) ||
-         oas_build_component_schemas_from_composite_types(schemas) ||
+  select oas_build_component_schemas_from_tables_and_composite_types(schemas) ||
          oas_build_component_schemas_headers()
 $$;
 
-create or replace function oas_build_component_schemas_from_tables(schemas text[])
+create or replace function oas_build_component_schemas_from_tables_and_composite_types(schemas text[])
 returns jsonb language sql stable as
 $$
-select jsonb_object_agg(x.table_name, x.oas_schema)
+with recursive all_rels as (
+  select *
+  from postgrest_get_all_tables_and_composite_types()
+),
+recursive_rels_in_schema as (
+  select *
+  from all_rels
+  where
+    -- All the tables or views in the exposed schemas
+    (table_schema = any(schemas) and (is_table or is_view))
+    -- All the composite types or tables that are present in function arguments
+    -- TODO: tweak postgrest_get_all_functions() or use another CTE for a more performant filter
+    or table_oid in (
+      select unnest(composite_args_ret)
+      from postgrest_get_all_functions(schemas)
+    )
+  union
+  -- Tables may have columns with composite or table types, so we recursively
+  -- look for these composite types or tables outside of the exposed schemas
+  -- in order to build the types correctly for the OpenAPI output.
+  select e.*
+  from all_rels e, recursive_rels_in_schema r
+  where e.table_oid = r.column_composite_relid
+),
+all_tables_and_composite_types as (
+  select
+    table_schema,
+    table_name,
+    table_description,
+    is_composite,
+    array_agg(column_name order by column_position) filter (where not column_is_nullable) AS required_cols,
+    jsonb_object_agg(
+      column_name,
+        case when column_item_data_type is null and column_composite_relid <> 0 then
+          oas_build_reference_to_schemas(column_data_type)
+        else
+          oas_schema_object(
+            description := column_description,
+            type := postgrest_pgtype_to_oastype(column_data_type),
+            format := column_data_type::text,
+            maxlength := column_character_maximum_length,
+            -- "default" :=  to_jsonb(info.column_default),
+            enum := to_jsonb(column_enums),
+            items :=
+              case
+              when column_item_data_type is null then
+                null
+              when column_composite_relid <> 0 then
+                oas_build_reference_to_schemas(column_item_data_type)
+              else
+                oas_schema_object(
+                  type := postgrest_pgtype_to_oastype(column_item_data_type),
+                  format := column_item_data_type::text
+                )
+              end
+          )
+        end order by column_position
+    ) as columns
+  from recursive_rels_in_schema
+  group by table_schema, table_name, table_description, is_composite
+)
+select jsonb_object_agg(x.component_name, x.oas_schema)
 from (
-  select table_name,
+  select case when is_composite then table_schema || '.' else '' end || table_name as component_name,
     oas_schema_object(
       description := table_description,
-      properties := columns,
+      properties := coalesce(columns, '{}'),
       required := required_cols,
       type := 'object'
     ) as oas_schema
-  from postgrest_get_all_tables(schemas)
-  where table_schema = any(schemas)
-) x;
-$$;
-
-create or replace function oas_build_component_schemas_from_composite_types(schemas text[])
-returns jsonb language sql stable as
-$$
-SELECT coalesce(jsonb_object_agg(x.ct_name, x.oas_schema), '{}')
-FROM (
-  SELECT comptype_schema || '.' || comptype_name as ct_name,
-         oas_schema_object(
-           description := comptype_description,
-           properties := columns,
-           type := 'object'
-         ) AS oas_schema
-  FROM postgrest_get_all_composite_types(schemas)
+  from all_tables_and_composite_types
 ) x;
 $$;
 
@@ -195,10 +239,11 @@ from (
       )
     ) as param_schema
   from (
-     select table_schema, table_name, unnest(all_cols) as column_name
-     from postgrest_get_all_tables(schemas)
+     select table_schema, is_table, is_view, table_name, column_name
+     from postgrest_get_all_tables_and_composite_types()
+     where table_schema = any(schemas)
+       and (is_table or is_view)
   ) _
-  where table_schema = any(schemas)
 ) x;
 $$;
 
@@ -617,8 +662,10 @@ from (
         )
       )
     end as may_be_empty_response
-  from postgrest_get_all_tables(schemas)
+  from postgrest_get_all_tables_and_composite_types()
   where table_schema = any(schemas)
+    and (is_table or is_view)
+  group by table_schema, table_name, insertable, is_table, is_view
 ) as x
 $$;
 
@@ -695,9 +742,11 @@ from (
         )
       )
     ) as oas_req_body
-  from postgrest_get_all_tables(schemas)
+  from postgrest_get_all_tables_and_composite_types()
   where table_schema = any(schemas)
+    and (is_table or is_view)
     and insertable
+  group by table_schema, table_name, insertable
 ) as x;
 $$;
 

sql/paths.sql

@@ -124,10 +124,12 @@ from (
         end
     ) as oas_path_item
   from (
-   select table_schema, table_name, table_description, insertable, updatable, deletable, unnest(all_cols) as column_name
-   from postgrest_get_all_tables(schemas)
+   select table_schema, table_name, table_description, insertable, updatable, deletable, column_name
+   from postgrest_get_all_tables_and_composite_types()
+   where table_schema = any(schemas)
+     and (is_table or is_view)
+   order by table_schema, table_name, column_position
   ) _
-  where table_schema = any(schemas)
   group by table_schema, table_name, table_description, insertable, updatable, deletable
 ) x;
 $$;