fix: issue 265 add cloud spanner functionality (#394)

* fix: issue 265 add cloud spanner functionality

*Add/override raw_sql() for cloud spanner
*Add SpannerCursor class to implement ibis client interface
*This is because current spanner client returns a dataframe which is not
compatible with the context manager that raw_query funtionality is
expecting

* fix: update test for raw_sql()

third_party/ibis/ibis_cloud_spanner/client.py

@@ -212,6 +212,48 @@ def execute(self):
         return dataframe_output
 
 
+class SpannerCursor:
+    """Spanner cursor.
+    This allows the Spanner client to reuse machinery in
+    :file:`ibis/client.py`.
+    """
+
+    def __init__(self, results):
+        self.results = results
+
+    def fetchall(self):
+        """Fetch all rows."""
+        result = self.results
+        return [tuple(row) for row in result]
+
+    @property
+    def columns(self):
+        """Return the columns of the result set."""
+        result = self.results
+        return [field.name for field in result.fields]
+
+    @property
+    def description(self):
+        """Get the fields of the result set's schema."""
+        return self.results.metadata.row_type
+
+    def __enter__(self):
+        # For compatibility when constructed from Query.execute()
+        """No-op for compatibility.
+        See Also
+        --------
+        ibis.client.Query.execute
+        """
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        """No-op for compatibility.
+        See Also
+        --------
+        ibis.client.Query.execute
+        """
+
+
 class CloudSpannerDatabase(Database):
     """A Cloud spanner dataset."""
 
@@ -240,17 +282,16 @@ def __init__(self, instance_id, database_id, project_id=None, credentials=None):
         self.spanner_client = spanner.Client(project=project_id)
         self.instance = self.spanner_client.instance(instance_id)
         self.database_name = self.instance.database(database_id)
-        (
-            self.data_instance,
-            self.dataset,
-        ) = parse_instance_and_dataset(instance_id, database_id)
+        (self.data_instance, self.dataset,) = parse_instance_and_dataset(
+            instance_id, database_id
+        )
         self.client = cs.Client()
 
     def _parse_instance_and_dataset(self, dataset):
         if not dataset and not self.dataset:
             raise ValueError("Unable to determine Cloud Spanner dataset.")
         instance, dataset = parse_instance_and_dataset(
-                self.data_instance,(dataset or self.dataset)
+            self.data_instance, (dataset or self.dataset)
         )
 
         return instance, dataset
@@ -366,6 +407,33 @@ def _execute(self, stmt, results=True, query_parameters=None):
             data_qry = pandas_df.to_pandas(snapshot, stmt, query_parameters)
         return data_qry
 
+    def raw_sql(self, query: str, results=False, params=None):
+        query_parameters = [
+            cloud_spanner_param(param, value) for param, value in (params or {}).items()
+        ]
+        spanner_client = spanner.Client()
+        instance_id = self.instance_id
+        instance = spanner_client.instance(instance_id)
+        database_id = self.dataset_id
+        database_1 = instance.database(database_id)
+        with database_1.snapshot() as snapshot:
+            if query_parameters:
+                param = {}
+                param_type = {}
+                for i in query_parameters:
+                    param.update(i["params"])
+                    param_type.update(i["param_types"])
+
+                results = snapshot.execute_sql(
+                    query, params=param, param_types=param_type
+                )
+
+            else:
+                results = snapshot.execute_sql(query)
+
+        sp = SpannerCursor(results)
+        return sp
+
     def database(self, name=None):
         if name is None and self.dataset is None:
             raise ValueError(
@@ -385,5 +453,3 @@ def dataset(self, database):
 
     def exists_database(self, name):
         return self.instance.database(name).exists()
-
-

third_party/ibis/ibis_cloud_spanner/tests/test_client.py

@@ -263,7 +263,7 @@ def test_scalar_param_date(alltypes, df, date_value):
 
 
 def test_raw_sql(client):
-    assert (client.raw_sql("SELECT 1")).iloc[0][0] == 1
+    assert (client.raw_sql("SELECT 1")).fetchall()[0][0] == 1
 
 
 def test_scalar_param_scope(alltypes):