Add common query params to components' parameters

sql/main.sql

@@ -46,9 +46,9 @@ select openapi_object(
   servers := openapi_server_objects(),
   paths := '{}',
   components := openapi_components_object(
-    schemas := postgrest_tables_to_openapi_schema_components(schemas) || postgrest_composite_types_to_openapi_schema_components(schemas)
+    schemas := postgrest_tables_to_openapi_schema_components(schemas) || postgrest_composite_types_to_openapi_schema_components(schemas),
+    parameters := postgrest_get_query_params()
   )
 )
 from postgrest_get_schema_description(schemas[1]) sd;
 $$;
-

sql/openapi.sql

@@ -1,4 +1,8 @@
--- Functions to build the the OpenAPI output
+-- Functions and types to build the the OpenAPI output
+
+-- TODO: create enum for openapi type e.g. string, number, etc.
+create type parameter_object_in as enum ('query', 'header', 'path', 'cookie');
+create type parameter_object_style as enum ('simple', 'form');
 
 create or replace function openapi_object(
   openapi text,
@@ -180,3 +184,34 @@ select json_build_object(
   '$ref', '#/components/schemas/' || ref
 );
 $$;
+
+create or replace function openapi_parameter_object(
+  name text,
+  "in" parameter_object_in,
+  description text default null,
+  required boolean default null,
+  deprecated boolean default null,
+  allowEmptyValue boolean default null,
+  style parameter_object_style default null,
+  explode boolean default null,
+  "schema" jsonb default null,
+  example boolean default null,
+  examples text default null
+)
+returns jsonb language sql as
+$$
+  -- TODO: Add missing logic between fields (e.g. example and examples are mutually exclusive)
+  select jsonb_build_object(
+    'name', name,
+    'in', "in",
+    'description', description,
+    'required', required,
+    'deprecated', deprecated,
+    'allowEmptyValue', allowEmptyValue,
+    'style', style,
+    'explode', explode,
+    'schema', "schema",
+    'example', example,
+    'examples', examples
+  )
+$$;

sql/postgrest.sql

@@ -509,3 +509,69 @@ returns text language sql as
 $$
 select '11.0.1 (4197d2f)'
 $$;
+
+create or replace function postgrest_get_query_params ()
+returns jsonb language sql as
+$$
+select jsonb_agg(param_object) from unnest(
+  array['select','order', 'limit', 'offset', 'on_conflict', 'columns'],
+  array[
+    openapi_parameter_object(
+      name := 'select',
+      "in" := 'query',
+      description := 'Vertical filtering of columns',
+      explode := false,
+      schema := openapi_schema_object(
+        type := 'array',
+        items := openapi_schema_object(type := 'string')
+      )
+    ),
+    openapi_parameter_object(
+      name := 'order',
+      "in" := 'query',
+      description := 'Ordering by column',
+      explode := false,
+      schema := openapi_schema_object(
+        type := 'array',
+        items := openapi_schema_object(type := 'string')
+      )
+    ),
+    openapi_parameter_object(
+      name := 'limit',
+      "in" := 'query',
+      description := 'Limit the number of rows returned',
+      explode := false,
+      schema := openapi_schema_object(
+        type := 'integer'
+      )
+    ),
+    openapi_parameter_object(
+      name := 'offset',
+      "in" := 'query',
+      description := 'Skip a certain number of rows',
+      explode := false,
+      schema := openapi_schema_object(
+        type := 'integer'
+      )
+    ),
+    openapi_parameter_object(
+      name := 'on_conflict',
+      "in" := 'query',
+      description := 'Columns that resolve the upsert conflict',
+      explode := false,
+      schema := openapi_schema_object(
+        type := 'string'
+      )
+    ),
+    openapi_parameter_object(
+      name := 'columns',
+      "in" := 'query',
+      description := 'Specify the only keys from the payload that will be inserted',
+      explode := false,
+      schema := openapi_schema_object(
+        type := 'string'
+      )
+    )
+  ]
+) as _(name, param_object);
+$$;