chore: Add support for named schema (#858)

* chore: Add support for named schema

* Fix

* Comments addressed

* Comments addressed

* Comments addressed

* Comments addressed

* Removing quote method for table name

* Fix

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* Update django_spanner/introspection.py

Co-authored-by: Knut Olav Løite <[email protected]>

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Knut Olav Løite <[email protected]>

Author: 3 people

django_spanner/introspection.py

@@ -29,26 +29,14 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
         TypeCode.NUMERIC: "DecimalField",
         TypeCode.JSON: "JSONField",
     }
-    if USE_EMULATOR:
-        # Emulator does not support table_type yet.
-        # https://github.com/GoogleCloudPlatform/cloud-spanner-emulator/issues/43
-        LIST_TABLE_SQL = """
-            SELECT
-                t.table_name, t.table_name
-            FROM
-                information_schema.tables AS t
-            WHERE
-                t.table_catalog = '' and t.table_schema = ''
-        """
-    else:
-        LIST_TABLE_SQL = """
-            SELECT
-                t.table_name, t.table_type
-            FROM
-                information_schema.tables AS t
-            WHERE
-                t.table_catalog = '' and t.table_schema = ''
-        """
+    LIST_TABLE_SQL = """
+        SELECT
+            t.table_name, t.table_type
+        FROM
+            information_schema.tables AS t
+        WHERE
+            t.table_catalog = '' and t.table_schema = @schema_name
+    """
 
     def get_field_type(self, data_type, description):
         """A hook for a Spanner database to use the cursor description to
@@ -76,7 +64,10 @@ def get_table_list(self, cursor):
         :rtype: list
         :returns: A list of table and view names in the current database.
         """
-        results = cursor.run_sql_in_snapshot(self.LIST_TABLE_SQL)
+        schema_name = self._get_schema_name(cursor)
+        results = cursor.run_sql_in_snapshot(
+            self.LIST_TABLE_SQL, params={"schema_name": schema_name}
+        )
         tables = []
         # The second TableInfo field is 't' for table or 'v' for view.
         for row in results:
@@ -159,8 +150,9 @@ def get_relations(self, cursor, table_name):
         :rtype: dict
         :returns: A dictionary representing column relationships to other tables.
         """
+        schema_name = self._get_schema_name(cursor)
         results = cursor.run_sql_in_snapshot(
-            '''
+            """
             SELECT
                 tc.COLUMN_NAME as col, ccu.COLUMN_NAME as ref_col, ccu.TABLE_NAME as ref_table
             FROM
@@ -174,8 +166,9 @@ def get_relations(self, cursor, table_name):
             ON
                 rc.UNIQUE_CONSTRAINT_NAME = ccu.CONSTRAINT_NAME
             WHERE
-                tc.TABLE_NAME="%s"'''
-            % self.connection.ops.quote_name(table_name)
+                tc.TABLE_SCHEMA=@schema_name AND tc.TABLE_NAME=@view_name
+            """,
+            params={"schema_name": schema_name, "view_name": table_name},
         )
         return {
             column: (referred_column, referred_table)
@@ -194,6 +187,7 @@ def get_primary_key_column(self, cursor, table_name):
         :rtype: str
         :returns: The name of the PK column.
         """
+        schema_name = self._get_schema_name(cursor)
         results = cursor.run_sql_in_snapshot(
             """
             SELECT
@@ -205,9 +199,9 @@ def get_primary_key_column(self, cursor, table_name):
             AS
                 ccu ON tc.CONSTRAINT_NAME = ccu.CONSTRAINT_NAME
             WHERE
-                tc.TABLE_NAME="%s" AND tc.CONSTRAINT_TYPE='PRIMARY KEY' AND tc.TABLE_SCHEMA=''
-            """
-            % self.connection.ops.quote_name(table_name)
+                tc.TABLE_NAME=@table_name AND tc.CONSTRAINT_TYPE='PRIMARY KEY' AND tc.TABLE_SCHEMA=@schema_name
+            """,
+            params={"schema_name": schema_name, "table_name": table_name},
         )
         return results[0][0] if results else None
 
@@ -224,18 +218,17 @@ def get_constraints(self, cursor, table_name):
         :returns: A dictionary with constraints.
         """
         constraints = {}
-        quoted_table_name = self.connection.ops.quote_name(table_name)
+        schema_name = self._get_schema_name(cursor)
 
         # Firstly populate all available constraints and their columns.
         constraint_columns = cursor.run_sql_in_snapshot(
-            '''
+            """
             SELECT
                 CONSTRAINT_NAME, COLUMN_NAME
             FROM
                 INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE
-               WHERE TABLE_NAME="{table}"'''.format(
-                table=quoted_table_name
-            )
+               WHERE TABLE_NAME=@table AND TABLE_SCHEMA=@schema_name""",
+            params={"table": table_name, "schema_name": schema_name},
         )
         for constraint, column_name in constraint_columns:
             if constraint not in constraints:
@@ -254,15 +247,14 @@ def get_constraints(self, cursor, table_name):
 
         # Add the various constraints by type.
         constraint_types = cursor.run_sql_in_snapshot(
-            '''
+            """
             SELECT
                 CONSTRAINT_NAME, CONSTRAINT_TYPE
             FROM
                 INFORMATION_SCHEMA.TABLE_CONSTRAINTS
             WHERE
-                TABLE_NAME="{table}"'''.format(
-                table=quoted_table_name
-            )
+                TABLE_NAME=@table AND TABLE_SCHEMA=@schema_name""",
+            params={"table": table_name, "schema_name": schema_name},
         )
         for constraint, constraint_type in constraint_types:
             already_added = constraint in constraints
@@ -303,14 +295,13 @@ def get_constraints(self, cursor, table_name):
             RIGHT JOIN
                 INFORMATION_SCHEMA.INDEX_COLUMNS AS idx_col
             ON
-                idx_col.INDEX_NAME = idx.INDEX_NAME AND idx_col.TABLE_NAME="{table}"
+                idx_col.INDEX_NAME = idx.INDEX_NAME AND idx_col.TABLE_NAME=@table AND idx_col.TABLE_SCHEMA=idx.TABLE_SCHEMA
             WHERE
-                idx.TABLE_NAME="{table}"
+                idx.TABLE_NAME=@table AND idx.TABLE_SCHEMA=@schema_name
             ORDER BY
                 idx_col.ORDINAL_POSITION
-            """.format(
-                table=quoted_table_name
-            )
+            """,
+            params={"table": table_name, "schema_name": schema_name},
         )
         for (
             index_name,
@@ -350,6 +341,7 @@ def get_key_columns(self, cursor, table_name):
         for all key columns in the given table.
         """
         key_columns = []
+        schema_name = self._get_schema_name(cursor)
         cursor.execute(
             """SELECT
                 tc.COLUMN_NAME as column_name,
@@ -366,10 +358,12 @@ def get_key_columns(self, cursor, table_name):
             ON
                 rc.CONSTRAINT_NAME = ccu.CONSTRAINT_NAME
             WHERE
-                tc.TABLE_NAME="{table}"
-            """.format(
-                table=self.connection.ops.quote_name(table_name)
-            )
+                tc.TABLE_NAME=@table AND tc.TABLE_SCHEMA=@schema_name
+            """,
+            params={"table": table_name, "schema_name": schema_name},
         )
         key_columns.extend(cursor.fetchall())
         return key_columns
+
+    def _get_schema_name(self, cursor):
+        return cursor.connection.current_schema