Update 'Table.patch()' to support patching schema.

See:
#1023 (comment).

Author: tseaver

gcloud/bigquery/table.py

@@ -423,8 +423,14 @@ def reload(self, client=None):
             method='GET', path=self.path)
         self._set_properties(api_response)
 
-    def patch(self, client=None, friendly_name=_MARKER, description=_MARKER,
-              location=_MARKER, expires=_MARKER, view_query=_MARKER):
+    def patch(self,
+              client=None,
+              friendly_name=_MARKER,
+              description=_MARKER,
+              location=_MARKER,
+              expires=_MARKER,
+              view_query=_MARKER,
+              schema=_MARKER):
         """API call:  update individual table properties via a PATCH request
 
         See
@@ -449,6 +455,9 @@ def patch(self, client=None, friendly_name=_MARKER, description=_MARKER,
         :type view_query: string
         :param view_query: SQL query defining the table as a view
 
+        :type schema: list of :class:`SchemaField`
+        :param schema: fields describing the schema
+
         :raises: ValueError for invalid value types.
         """
         client = self._require_client(client)
@@ -476,6 +485,13 @@ def patch(self, client=None, friendly_name=_MARKER, description=_MARKER,
             else:
                 partial['view'] = {'query': view_query}
 
+        if schema is not _MARKER:
+            if schema is None:
+                partial['schema'] = None
+            else:
+                partial['schema'] = {
+                    'fields': self._build_schema_resource(schema)}
+
         api_response = client.connection.api_request(
             method='PATCH', path=self.path, data=partial)
         self._set_properties(api_response)

gcloud/bigquery/test_table.py

@@ -569,6 +569,7 @@ def test_patch_w_alternate_client(self):
         import datetime
         import pytz
         from gcloud.bigquery._helpers import _millis
+        from gcloud.bigquery.table import SchemaField
         PATH = 'projects/%s/datasets/%s/tables/%s' % (
             self.PROJECT, self.DS_NAME, self.TABLE_NAME)
         QUERY = 'select fullname, age from person_ages'
@@ -586,9 +587,11 @@ def test_patch_w_alternate_client(self):
         client2 = _Client(project=self.PROJECT, connection=conn2)
         dataset = _Dataset(client1)
         table = self._makeOne(self.TABLE_NAME, dataset=dataset)
+        full_name = SchemaField('full_name', 'STRING', mode='REQUIRED')
+        age = SchemaField('age', 'INTEGER', mode='OPTIONAL')
 
         table.patch(client=client2, view_query=QUERY, location=LOCATION,
-                    expires=self.EXP_TIME)
+                    expires=self.EXP_TIME, schema=[full_name, age])
 
         self.assertEqual(len(conn1._requested), 0)
         self.assertEqual(len(conn2._requested), 1)
@@ -599,10 +602,38 @@ def test_patch_w_alternate_client(self):
             'view': {'query': QUERY},
             'location': LOCATION,
             'expirationTime': _millis(self.EXP_TIME),
+            'schema': {'fields': [
+                {'name': 'full_name', 'type': 'STRING', 'mode': 'REQUIRED'},
+                {'name': 'age', 'type': 'INTEGER', 'mode': 'OPTIONAL'}]},
         }
         self.assertEqual(req['data'], SENT)
         self._verifyResourceProperties(table, RESOURCE)
 
+    def test_patch_w_schema_None(self):
+        # Simulate deleting schema:  not sure if back-end will actually
+        # allow this operation, but the spec says it is optional.
+        PATH = 'projects/%s/datasets/%s/tables/%s' % (
+            self.PROJECT, self.DS_NAME, self.TABLE_NAME)
+        DESCRIPTION = 'DESCRIPTION'
+        TITLE = 'TITLE'
+        RESOURCE = self._makeResource()
+        RESOURCE['description'] = DESCRIPTION
+        RESOURCE['friendlyName'] = TITLE
+        conn = _Connection(RESOURCE)
+        client = _Client(project=self.PROJECT, connection=conn)
+        dataset = _Dataset(client)
+        table = self._makeOne(self.TABLE_NAME, dataset=dataset)
+
+        table.patch(schema=None)
+
+        self.assertEqual(len(conn._requested), 1)
+        req = conn._requested[0]
+        self.assertEqual(req['method'], 'PATCH')
+        SENT = {'schema': None}
+        self.assertEqual(req['data'], SENT)
+        self.assertEqual(req['path'], '/%s' % PATH)
+        self._verifyResourceProperties(table, RESOURCE)
+
     def test_update_w_bound_client(self):
         from gcloud.bigquery.table import SchemaField
         PATH = 'projects/%s/datasets/%s/tables/%s' % (