hasura · 0x777 · Jun 4, 2019 · May 27, 2019 · May 27, 2019 · May 27, 2019
@@ -115,8 +115,8 @@ First install the `pg_trgm <https://www.postgresql.org/docs/current/pgtrgm.html>
 Next create a GIN (or GIST) index in your database for the columns you'll be querying:
 
 .. code-block:: sql
-      
-  CREATE INDEX address_gin_idx ON property 
+
+  CREATE INDEX address_gin_idx ON property
   USING GIN ((unit || ' ' || num || ' ' || street || ' ' || city || ' ' || region || ' ' || postcode) gin_trgm_ops);
 
 And finally create the custom SQL function in the Hasura console:
@@ -127,7 +127,7 @@ And finally create the custom SQL function in the Hasura console:
   RETURNS SETOF property AS $$
       SELECT *
       FROM property
-      WHERE 
+      WHERE
         search <% (unit || ' ' || num || ' ' || street || ' ' || city || ' ' || region || ' ' || postcode)
       ORDER BY
         similarity(search, (unit || ' ' || num || ' ' || street || ' ' || city || ' ' || region || ' ' || postcode)) DESC
@@ -178,6 +178,8 @@ Assuming the ``property`` table is being tracked, you can use the custom functio
       }
     }
 
+.. _custom_functions_postgis:
+
 Example: PostGIS functions
 **************************
 
@@ -187,7 +189,7 @@ Say you have 2 tables, for user and landmark location data, with the following d
 popular spatial database extension,* `PostGIS <https://postgis.net/>`__):
 
 .. code-block:: sql
-      
+
   -- User location data
   CREATE TABLE user_location (
     user_id INTEGER PRIMARY KEY,
@@ -211,9 +213,8 @@ doesn't exist, let's first create this table and then create our location search
 - create and track the following table:
 
   .. code-block:: sql
-
-      -- SETOF table
 
+      -- SETOF table
       CREATE TABLE user_landmarks (
         user_id INTEGER,
         location GEOGRAPHY(Point),
@@ -224,9 +225,8 @@ doesn't exist, let's first create this table and then create our location search
 
   .. code-block:: plpgsql
 
-      -- function returns a list of landmarks near a user based on the 
+      -- function returns a list of landmarks near a user based on the
       -- input arguments distance_kms and userid
-
       CREATE FUNCTION search_landmarks_near_user(userid integer, distance_kms integer)
       RETURNS SETOF user_landmarks AS $$
         SELECT  A.user_id, A.location,
@@ -320,7 +320,7 @@ As with tables, arguments like ``where``, ``limit``, ``order_by``, ``offset``, e
 function-based queries.
 
 **For example**, limit the number of articles returned by the function defined in the text-search example above:
-    
+
 .. code-block:: graphql
 
     query {
@@ -334,11 +334,72 @@ function-based queries.
       }
     }
 
+Using argument default values for custom functions
+**************************************************
+
+If you omit an argument in ``args`` input field then GraphQL Engine executes the SQL function without the argument.
+Hence, the function will use the default value of that argument set in its definition.
+
+**For example:** In the above :ref:`PostGIS functions example <custom_functions_postgis>`, the function
+definition can be updated as follows:
+
+.. code-block:: plpgsql
+
+      -- input arguments distance_kms (default: 2) and userid
+      CREATE FUNCTION search_landmarks_near_user(userid integer, distance_kms integer default 2)
+
+Search nearby landmarks with ``distance_kms`` default value which is 2 kms:
+
+.. graphiql::
+  :view_only:
+  :query:
+    query {
+      search_landmarks_near_user(
+        args: {userid: 3}
+      ){
+        user_id
+        location
+        nearby_landmarks
+      }
+    }
+  :response:
+    {
+      "data": {
+        "search_landmarks_near_user": [
+          {
+            "user_id": 3,
+            "location": {
+              "type": "Point",
+              "crs": {
+                "type": "name",
+                "properties": {
+                  "name": "urn:ogc:def:crs:EPSG::4326"
+                }
+              },
+              "coordinates": [
+                12.9406589,
+                77.6185572
+              ]
+            },
+            "nearby_landmarks": [
+              {
+                "id": 3,
+                "name": "blue tokai",
+                "type": "coffee shop",
+                "location": "0101000020E61000004E74A785DCF22940BE44060399665340"
+              }
+            ]
+          }
+        ]
+      }
+    }
+
+
 Permissions for custom function queries
 ---------------------------------------
 
 Access control permissions configured for the ``SETOF`` table of a function are also applicable to the function itself.
 
 **For example**, in our text-search example above, if the role ``user`` doesn't have the requisite permissions to view
 the table ``article``, a validation error will be thrown if the ``search_articles`` query is run using the ``user``
-role.
+role.
@@ -305,7 +305,7 @@ convertSelect
      )
   => SelOpCtx -> Field -> m QueryRootFldUnresolved
 convertSelect opCtx fld =
-  withPathK "selectionSet" $ fmap QRFSimple $
+  withPathK "selectionSet" $ QRFSimple <$>
   fromField qt permFilter permLimit fld
   where
     SelOpCtx qt _ permFilter permLimit = opCtx
@@ -316,7 +316,7 @@ convertSelectByPKey
      )
   => SelPkOpCtx -> Field -> m QueryRootFldUnresolved
 convertSelectByPKey opCtx fld =
-  withPathK "selectionSet" $ fmap QRFPk $
+  withPathK "selectionSet" $ QRFPk <$>
     fromFieldByPKey qt colArgMap permFilter fld
   where
     SelPkOpCtx qt _ permFilter colArgMap = opCtx
@@ -400,22 +400,21 @@ convertAggSelect
      )
   => SelOpCtx -> Field -> m QueryRootFldUnresolved
 convertAggSelect opCtx fld =
-  withPathK "selectionSet" $ fmap QRFAgg $
+  withPathK "selectionSet" $ QRFAgg <$>
   fromAggField qt permFilter permLimit fld
   -- return $ RS.selectAggQuerySQL selData
   where
     SelOpCtx qt _ permFilter permLimit = opCtx
 
 parseFunctionArgs
   ::( MonadError QErr m)
-  => FuncArgSeq -> AnnInpVal -> m [AnnPGVal]
-parseFunctionArgs argSeq val =
-  flip withObject val $ \nTy obj ->
-    fmap toList $ forM argSeq $ \(FuncArgItem argName) -> do
-      argVal <- onNothing (OMap.lookup argName obj) $ throw500 $
-                "argument " <> showName argName <> " required in input type "
-                <> showNamedTy nTy
-      asPGColVal argVal
+  => FuncArgSeq -> AnnInpVal -> m [UnresolvedVal]
+parseFunctionArgs argSeq val = fmap catMaybes $
+  flip withObject val $ \_ obj ->
+    fmap toList $ forM argSeq $ \(FuncArgItem argName) ->
+      forM (OMap.lookup argName obj) $ fmap (maybe nullSQL UVPG) . asPGColValM
+  where
+    nullSQL = UVSQL $ S.SEUnsafe "NULL"
 
 fromFuncQueryField
   :: (MonadError QErr m)
@@ -425,7 +424,7 @@ fromFuncQueryField
   -> m (RS.AnnFnSelG s UnresolvedVal)
 fromFuncQueryField fn qf argSeq fld = fieldAsPath fld $ do
   funcArgsM <- withArgM (_fArguments fld) "args" $ parseFunctionArgs argSeq
-  let funcArgs = maybe [] (map UVPG) funcArgsM
+  let funcArgs = fromMaybe [] funcArgsM
   RS.AnnFnSel qf funcArgs <$> fn fld
 
 convertFuncQuerySimple
@@ -437,7 +436,7 @@ convertFuncQuerySimple
      )
   => FuncQOpCtx -> Field -> m QueryRootFldUnresolved
 convertFuncQuerySimple funcOpCtx fld =
-  withPathK "selectionSet" $ fmap QRFFnSimple $
+  withPathK "selectionSet" $ QRFFnSimple <$>
     fromFuncQueryField (fromField qt permFilter permLimit) qf argSeq fld
   where
     FuncQOpCtx qt _ permFilter permLimit qf argSeq = funcOpCtx
@@ -451,7 +450,7 @@ convertFuncQueryAgg
      )
   => FuncQOpCtx -> Field -> m QueryRootFldUnresolved
 convertFuncQueryAgg funcOpCtx fld =
-  withPathK "selectionSet" $ fmap QRFFnAgg $
+  withPathK "selectionSet" $ QRFFnAgg <$>
     fromFuncQueryField (fromAggField qt permFilter permLimit) qf argSeq fld
   where
     FuncQOpCtx qt _ permFilter permLimit qf argSeq = funcOpCtx

@@ -592,8 +592,8 @@ mkFuncArgsInp funcInfo =
     argInps = procFuncArgs funcArgs mkInpVal
 
     mkInpVal ty t =
-      InpValInfo Nothing (G.Name t) Nothing $ G.toGT $
-      G.toNT $ mkScalarTy ty
+      InpValInfo Nothing (G.Name t) Nothing $
+      G.toGT $ mkScalarTy ty
 
 -- table_set_input
 mkUpdSetTy :: QualifiedTable -> G.NamedType

@@ -0,0 +1,33 @@
+description: Run queries on SQL my_add function with null input values
+url: /v1/graphql
+status: 200
+response:
+  data:
+    my_add:
+    - result: 5
+    my_add_null:
+    - result:
+    my_add_default:
+    - result: 12
+query:
+  query: |
+    query {
+      my_add(
+        args: {first: 2 second: 3}
+      ){
+        result
+      }
+      # input null value
+      my_add_null: my_add(
+        args: {first: null second: 2}
+      ){
+        result
+      }
+      # omiting 'second' parameter to consider
+      # it's default value in postgres
+      my_add_default: my_add(
+        args: {first: 2}
+      ){
+        result
+      }
+    }
@@ -71,5 +71,26 @@ args:
     name: get_test
     schema: public
 
+# custom add sql function
+- type: run_sql
+  args:
+    sql: |
+      CREATE TABLE integer_column
+      (
+        result integer
+      );
 
+      CREATE FUNCTION my_add (first integer, second integer DEFAULT 10)
+      RETURNS SETOF integer_column as $$
+        SELECT q.* FROM (VALUES (first + second)) as q
+      $$ LANGUAGE SQL STABLE;
 
+- type: track_table
+  args:
+    name: integer_column
+    schema: public
+
+- type: track_function
+  args:
+    name: my_add
+    schema: public
@@ -6,4 +6,5 @@ args:
     sql: |
       DROP TABLE post cascade;
       DROP TABLE test cascade;
+      DROP TABLE integer_column cascade;
     cascade: true
@@ -383,6 +383,9 @@ def test_overloading_function_error(self, hge_ctx):
     def test_query_get_test_uuid(self, hge_ctx):
         check_query_f(hge_ctx, self.dir() + '/query_get_test_uuid.yaml')
 
+    def test_query_my_add(self, hge_ctx):
+        check_query_f(hge_ctx, self.dir() + '/query_my_add.yaml')
+
     @classmethod
     def dir(cls):
         return 'queries/graphql_query/functions'