docs: add single object mutations docs (close #4622) (#4625)

CHANGELOG.md

@@ -65,6 +65,7 @@ Read more about the session argument for computed fields in the [docs](https://h
 - cli: list all available commands in root command help (fix #4623)
 - docs: add section on actions vs. remote schemas to actions documentation (#4284)
 - docs: fix wrong info about excluding scheme in CORS config (#4685)
+- docs: add single object mutations docs (close #4622) (#4625)
 - docs: add docs page on query performance (close #2316) (#3693)
 - docs: add a sample Caddyfile for Caddy 2 in enable-https section (#4710)
 

docs/graphql/manual/api-reference/graphql-api/mutation.rst

@@ -14,8 +14,8 @@ API Reference - Mutation
  
 .. _insert_upsert_syntax:
 
-Insert / upsert syntax
+**insert** (upsert) syntax
-----------------------
+--------------------------
 
 .. code-block:: none
 
@@ -99,8 +99,8 @@ Insert / upsert syntax
 
 .. _insert_upsert_one_syntax:
 
-Insert / upsert one syntax
+**insert_one** syntax
---------------------------
+---------------------
 
 .. code-block:: none
 
@@ -157,11 +157,89 @@ Insert / upsert one syntax
       }
     }
 
+.. _update_by_pk_syntax:
+
+**update_by_pk** syntax
+-----------------------
+
+.. code-block:: none
+
+    mutation [<mutation-name>] {
+      <mutation-field-name> (
+        [pk-columns-argument!],
+        [set-argument!]
+      )
+      <object-fields>
+    }
+
+.. list-table::
+   :header-rows: 1
+
+   * - Key
+     - Required
+     - Schema
+     - Description
+   * - mutation-name
+     - false
+     - Value
+     - Name of mutation for observability
+   * - mutation-field-name
+     - true
+     - Value
+     - Name of the auto-generated update mutation field, e.g. *update_author_by_pk*
+   * - pk-columns-argument
+     - true
+     - pkColumnsArgExp_
+     - Primary key(s) for row(s) to be updated
+   * - set-argument
+     - false
+     - setArgExp_
+     - Data to be updated in the table
+   * - inc-argument
+     - false
+     - incArgExp_
+     - Integer value to be incremented to Int columns in the table
+   * - append-argument
+     - false
+     - appendArgExp_
+     - JSON value to be appended to JSONB columns in the table
+   * - prepend-argument
+     - false
+     - prependArgExp_
+     - JSON value to be prepended to JSONB columns in the table
+   * - delete-key-argument
+     - false
+     - deleteKeyArgExp_
+     - Key to be deleted in the value of JSONB columns in the table
+   * - delete-elem-argument
+     - false
+     - deleteElemArgExp_
+     - Array element to be deleted in the value of JSONB columns in the table
+   * - delete-at-path-argument
+     - false
+     - deleteAtPathArgExp_
+     - Element at path to be deleted in the value of JSONB columns in the table
+
+**E.g. UPDATE BY PK**:
+
+.. code-block:: graphql
+
+    mutation update_articles {
+      update_article_by_pk (
+        pk_columns: {
+          id: 1
+        }
+        _set: { is_published: true }
+      ) {
+        id
+        title
+      }
+    }
 
 .. _update_syntax:
 
-Update syntax
+**update** syntax
--------------
+-----------------
 
 .. code-block:: none
 
@@ -238,10 +316,54 @@ Update syntax
       }
     }
 
+.. _delete_by_pk_syntax:
+
+**delete_by_pk** syntax
+-----------------------
+
+.. code-block:: none
+
+    mutation [<mutation-name>] {
+      <mutation-field-name> (
+        column1: value1
+        column2: value2
+      )
+      <object-fields>
+    }
+
+.. list-table::
+   :header-rows: 1
+
+   * - Key
+     - Required
+     - Schema
+     - Description
+   * - mutation-name
+     - false
+     - Value
+     - Name of mutation for observability
+   * - mutation-field-name
+     - true
+     - Value
+     - Name of the auto-generated delete mutation field, e.g. *delete_author_by_pk*
+
+**E.g. DELETE BY PK**:
+
+.. code-block:: graphql
+
+    mutation delete_articles {
+      delete_article_by_pk (
+        id: 1
+      ) {
+        id
+        title
+      }
+    }
+
 .. _delete_syntax:
 
-Delete syntax
+**delete** syntax
--------------
+-----------------
 
 .. code-block:: none
 
@@ -431,6 +553,29 @@ E.g.:
       where: {id: {_lt: 1}}
     }
 
+.. _pkColumnsArgExp:
+
+**pk_columns** argument
+^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``pk_columns`` argument is used to identify an object by its primary key columns in *update* mutations. 
+
+.. code-block:: none
+
+    pk_columns: {
+      column-1: value-1
+      column-2: value-2
+    }
+
+E.g.:
+
+.. code-block:: graphql
+
+    pk_columns: {
+      id: 1
+      name: "Harry"
+    }
+
 .. _whereArgExp:
 
 **where** argument

docs/graphql/manual/api-reference/graphql-api/query.rst

@@ -12,8 +12,8 @@ API Reference - Query / Subscription
   :depth: 3
   :local:
 
-Query / subscription syntax
+**query** / **subscription** syntax
----------------------------
+-----------------------------------
 
 .. code-block:: none
 
@@ -69,6 +69,57 @@ Query / subscription syntax
 
     For more examples and details of usage, please see :ref:`this <queries>`.
 
+**query_by_pk** / **subscription_by_pk** syntax
+-----------------------------------------------
+
+.. code-block:: none
+
+    query|subscription [<op-name>] {
+      <query-field-name> (
+        column1: value1
+        column2: value2
+      )
+      <object-fields>
+    }
+
+.. list-table::
+   :header-rows: 1
+
+   * - Key
+     - Required
+     - Schema
+     - Description
+   * - op-name
+     - false
+     - Value
+     - Name query/subscription for observability
+   * - query-field-name
+     - true
+     - Value
+     - Name of the auto-generated query field, e.g. *article_by_pk*
+
+**E.g. QUERY BY PK**:
+
+.. code-block:: graphql
+
+    query {
+      article_by_pk(id: 1) {
+        id
+        title
+      }
+    }
+
+**E.g. SUBSCRIPTION BY PK**:
+
+.. code-block:: graphql
+
+    subscription {
+      article_by_pk(id: 1) {
+        id
+        title
+      }
+    }
+
 Syntax definitions
 ------------------
 

docs/graphql/manual/api-reference/schema-metadata-api/table-view.rst

@@ -133,8 +133,11 @@ Add a table/view ``author``:
               "select_by_pk": "Author",
               "select_aggregate": "AuthorAggregate",
               "insert": "AddAuthors",
+              "insert_one":"AddAuthor",
               "update": "UpdateAuthors",
-              "delete": "DeleteAuthors"
+              "update_by_pk": "UpdateAuthor",
+              "delete": "DeleteAuthors",
+              "delete_by_pk": "DeleteAuthor"
            },
            "custom_column_names": {
               "id": "authorId"
@@ -199,28 +202,40 @@ Custom Root Fields
      - Description
    * - select
      - false
-     - `String`
+     - ``String``
      - Customise the ``<table-name>`` root field
    * - select_by_pk
      - false
-     - `String`
+     - ``String``
      - Customise the ``<table-name>_by_pk`` root field
    * - select_aggregate
      - false
-     - `String`
+     - ``String``
      - Customise the ``<table-name>_aggregete`` root field
    * - insert
      - false
-     - `String`
+     - ``String``
      - Customise the ``insert_<table-name>`` root field
+   * - insert_one
+     - false
+     - ``String``
+     - Customise the ``insert_<table-name>_one`` root field
    * - update
      - false
-     - `String`
+     - ``String``
      - Customise the ``update_<table-name>`` root field
+   * - update_by_pk
+     - false
+     - ``String``
+     - Customise the ``update_<table-name>_by_pk`` root field
    * - delete
      - false
-     - `String`
+     - ``String``
      - Customise the ``delete_<table-name>`` root field
+   * - delete_by_pk
+     - false
+     - ``String``
+     - Customise the ``delete_<table-name>_by_pk`` root field
 
 .. _set_table_custom_fields:
 
@@ -249,8 +264,11 @@ Set custom fields for table/view ``author``:
            "select_by_pk": "Author",
            "select_aggregate": "AuthorAggregate",
            "insert": "AddAuthors",
+           "insert_one":"AddAuthor",
            "update": "UpdateAuthors",
-           "delete": "DeleteAuthors"
+           "update_by_pk": "UpdateAuthor",
+           "delete": "DeleteAuthors",
+           "delete_by_pk": "DeleteAuthor"
         },
         "custom_column_names": {
            "id": "authorId"

docs/graphql/manual/mutations/delete.rst

@@ -27,10 +27,16 @@ Auto-generated delete mutation schema
   type article_mutation_response {
     # number of affected rows by the mutation
     affected_rows: Int!
-    #data of the affected rows by the mutation
+    # data of the affected rows by the mutation
     returning: [article!]!
   }
 
+  # single object delete (supported from v1.2.0)
+  delete_article_by_pk (
+    # all primary key columns args
+    id: Int
+  ): article
+
 As you can see from the schema:
 
 - The ``where`` argument is compulsory to filter rows to be deleted. See :ref:`Filter queries <filter_queries>`
@@ -45,8 +51,68 @@ See the :ref:`delete mutation API reference <delete_syntax>` for the full specif
   If a table is not in the ``public`` Postgres schema, the delete mutation field will be of the format
   ``delete_<schema_name>_<table_name>``.
 
-Delete based on an object's fields
+Delete an object by its primary key
-----------------------------------
+-----------------------------------
+
+You can delete a single object in a table using the primary key.
+The output type is the nullable table object. The mutation returns the deleted
+row object or ``null`` if the row does not exist.
+
+
+**Example:** Delete an article where ``id`` is ``1``:
+
+.. graphiql::
+  :view_only:
+  :query:
+    mutation delete_an_object {
+      delete_article_by_pk (
+        id: 1
+      ) {
+        id
+        title
+        user_id
+      }
+    }
+  :response:
+    {
+      "data": {
+        "delete_article_by_pk": {
+          "id": 1,
+          "title": "Article 1",
+          "user_id": 1
+        }
+      }
+    }
+
+**Example:** Delete a non-existent article:
+
+.. graphiql::
+  :view_only:
+  :query:
+    mutation delete_an_object {
+      delete_article_by_pk (
+        id: 100
+      ) {
+        id
+        title
+        user_id
+      }
+    }
+  :response:
+    {
+      "data": {
+        "delete_article_by_pk": null
+      }
+    }
+
+.. admonition:: Supported from
+
+   The ``delete_<table>_by_pk`` mutation is supported in versions ``v1.2.0``
+   and above.
+
+
+Delete objects based on an their fields
+---------------------------------------
 **Example:** Delete all articles rated less than 3:
 
 .. graphiql::
@@ -69,8 +135,8 @@ Delete based on an object's fields
     }
 
 
-Delete based on a nested object's fields
+Delete objects based on nested objects' fields
-----------------------------------------
+----------------------------------------------
 **Example:** Delete all articles written by a particular author:
 
 .. graphiql::

docs/graphql/manual/mutations/insert.rst

@@ -28,7 +28,7 @@ Auto-generated insert mutation schema
   type article_mutation_response {
     # number of affected rows by the mutation
     affected_rows: Int!
-    #data of the affected rows by the mutation
+    # data of the affected rows by the mutation
     returning: [article!]!
   }
 

docs/graphql/manual/mutations/update.rst

@@ -29,10 +29,18 @@ Auto-generated update mutation schema
   type article_mutation_response {
     # number of affected rows by the mutation
     affected_rows: Int!
-    #data of the affected rows by the mutation
+    # data of the affected rows by the mutation
     returning: [article!]!
   }
 
+  # single object update (supported from v1.2.0)
+  update_article_by_pk (
+    _inc: article_inc_input
+    _set: article_set_input
+    # primary key columns arg
+    pk_columns: article_pk_columns_input!
+  ): article
+
 As you can see from the schema:
 
 - The ``where`` argument is compulsory to filter rows to be updated. See :ref:`Filter queries <filter_queries>`
@@ -50,20 +58,77 @@ See the :ref:`update mutation API reference <update_syntax>` for the full specif
   - If a table is not in the ``public`` Postgres schema, the update mutation field will be of the format
     ``update_<schema_name>_<table_name>``.
 
-Update based on an object's fields
+Update an object by its primary key
-----------------------------------
+-----------------------------------
-**Example:** Update the ``title``, ``content`` and ``rating`` of the article with a given ``id``:
+
+You can update a single object in a table using the primary key.
+The output type is the nullable table object. The mutation returns the updated
+row object or ``null`` if the row does not exist.
+
+**Example:** Update an article where ``id`` is ``1``:
+
+.. graphiql::
+  :view_only:
+  :query:
+    mutation update_an_article {
+      update_article_by_pk (
+        pk_columns: {id: 1}
+        _set: { is_published: true }
+      ) {
+        id
+        is_published
+      }
+    }
+  :response:
+    {
+      "data": {
+        "update_article_by_pk": {
+          "id": 1,
+          "is_published": true
+        }
+      }
+    }
+
+**Example:** Update a non-existent article:
+
+.. graphiql::
+  :view_only:
+  :query:
+    mutation update_an_article {
+      update_article_by_pk (
+        pk_columns: {id: 100}
+        _set: { is_published: true }
+      ) {
+        id
+        is_published
+      }
+    }
+  :response:
+    {
+      "data": {
+        "update_article_by_pk": null
+      }
+    }
+
+.. admonition:: Supported from
+
+   The ``update_<table>_by_pk`` mutation is supported in versions ``v1.2.0``
+   and above.
+
+
+Update objects based on their fields
+------------------------------------
+**Example:** Update the ``rating`` and ``is_published`` of articles with a low ``rating``:
 
 .. graphiql::
   :view_only:
   :query:
     mutation update_article {
       update_article(
-        where: {id: {_eq: 3}},
+        where: {rating: {_lte: 2}},
         _set: {
-          title: "lorem ipsum",
+          rating: 1,
-          content: "dolor sit amet",
+          is_published: false
-          rating: 2
         }
       ) {
         affected_rows
@@ -72,6 +137,7 @@ Update based on an object's fields
           title
           content
           rating
+          is_published
         }
       }
     }
@@ -79,13 +145,21 @@ Update based on an object's fields
     {
       "data": {
         "update_article": {
-          "affected_rows": 1,
+          "affected_rows": 2,
           "returning": [
             {
               "id": 3,
-              "title": "lorem ipsum",
+              "title": "article 3",
-              "content": "dolor sit amet",
+              "content": "lorem ipsum dolor sit amet",
-              "rating": 2
+              "rating": 1,
+              "is_published": false
+            },
+            {
+              "id": 6,
+              "title": "article 6",
+              "content": "lorem ipsum dolor sit amet",
+              "rating": 1,
+              "is_published": false
             }
           ]
         }
@@ -97,9 +171,9 @@ Using variables:
 .. graphiql::
   :view_only:
   :query:
-    mutation update_article($id: Int, $changes: article_set_input) {
+    mutation update_article($rating: Int, $changes: article_set_input) {
       update_article(
-        where: {id: {_eq: $id}},
+        where: {rating: {_lte: $rating}},
         _set: $changes
       ) {
         affected_rows
@@ -108,6 +182,7 @@ Using variables:
           title
           content
           rating
+          is_published
         }
       }
     }
@@ -115,13 +190,21 @@ Using variables:
     {
       "data": {
         "update_article": {
-          "affected_rows": 1,
+          "affected_rows": 2,
           "returning": [
             {
               "id": 3,
-              "title": "lorem ipsum",
+              "title": "article 3",
-              "content": "dolor sit amet",
+              "content": "lorem ipsum dolor sit amet",
-              "rating": 2
+              "rating": 1,
+              "is_published": false
+            },
+            {
+              "id": 6,
+              "title": "article 6",
+              "content": "lorem ipsum dolor sit amet",
+              "rating": 1,
+              "is_published": false
             }
           ]
         }
@@ -129,11 +212,10 @@ Using variables:
     }
   :variables:
     {
-      "id": 3,
+      "rating": 2,
       "changes": {
-        "title": "lorem ipsum",
+        "rating": 1,
-        "content": "dolor sit amet",
+        "is_published": false,
-        "rating": 2
       }
     }
 
@@ -142,13 +224,12 @@ OR
 .. graphiql::
   :view_only:
   :query:
-    mutation update_article($id: Int, $title: String, $content: String, $rating: Int) {
+    mutation update_article($ratingLimit: Int, $rating: Int, $isPublished: Boolean) {
       update_article(
-        where: {id: {_eq: $id}},
+        where: {rating: {_lte: $ratingLimit}},
         _set: {
-          title: $title,
+          rating: $rating,
-          content: $content,
+          is_published: $isPublished,
-          rating: $rating
         }
       ) {
         affected_rows
@@ -157,6 +238,7 @@ OR
           title
           content
           rating
+          is_published
         }
       }
     }
@@ -164,13 +246,21 @@ OR
     {
       "data": {
         "update_article": {
-          "affected_rows": 1,
+          "affected_rows": 2,
           "returning": [
             {
               "id": 3,
-              "title": "lorem ipsum",
+              "title": "article 3",
-              "content": "dolor sit amet",
+              "content": "lorem ipsum dolor sit amet",
-              "rating": 2
+              "rating": 1,
+              "is_published": false
+            },
+            {
+              "id": 6,
+              "title": "article 6",
+              "content": "lorem ipsum dolor sit amet",
+              "rating": 1,
+              "is_published": false
             }
           ]
         }
@@ -178,14 +268,13 @@ OR
     }
   :variables:
     {
-      "id": 3,
+      "ratingLimit": 2,
-      "title": "lorem ipsum",
+      "rating": 1,
-      "content": "dolor sit amet",
+      "isPublished": false
-      "rating": 2
     }
 
-Update based on a nested object's fields
+Update objects based on nested objects' fields
-----------------------------------------
+----------------------------------------------
 **Example:** Reset the ``rating`` of all articles authored by "Sidney":
 
 .. graphiql::
@@ -551,5 +640,3 @@ one to delete all the existing objects and one to add a list of new nested objec
     {
       "author_id": 21
     }
-
-

docs/graphql/manual/queries/index.rst

@@ -40,6 +40,12 @@ Auto-generated query field schema
       order_by:  [author_order_by!]
     ): [author]
 
+    # single object select
+    author_by_pk (
+      # all primary key columns args
+      id: Int!
+    ): author
+
 See the :ref:`Query API reference <graphql_api_query>` for the full specifications
 
 .. note::

docs/graphql/manual/queries/query-filters.rst

@@ -1727,7 +1727,13 @@ The TRUE expression ( **{ }** )
 
 The expression ``{}`` evaluates to ``true`` for all objects.
 
-**For example**, any query with the condition ``{ where: {} }`` will return all objects without applying any filter.
+**For example**:
+
+- any query with the condition ``{ where: {} }`` will return all objects without
+  applying any filter.
+
+- any query with the condition ``{ where: { nested_object: {} } }`` will return all
+  objects for which atleast one ``nested_object`` exists.
 
 .. _null_value_evaluation: