pg: fix has_privileges function to quote schema and table names (#7574)

Author: sarvesh68

redash/query_runner/pg.py

@@ -223,7 +223,7 @@ def _get_tables(self, schema):
         AND a.attnum > 0
         AND NOT a.attisdropped
         WHERE c.relkind = 'm'
-        AND has_table_privilege(s.nspname || '.' || c.relname, 'select')
+        AND has_table_privilege(quote_ident(s.nspname) || '.' || quote_ident(c.relname), 'select')
         AND has_schema_privilege(s.nspname, 'usage')
 
         UNION
@@ -234,7 +234,7 @@ def _get_tables(self, schema):
                data_type
         FROM information_schema.columns
         WHERE table_schema NOT IN ('pg_catalog', 'information_schema')
-        AND has_table_privilege(table_schema || '.' || table_name, 'select')
+        AND has_table_privilege(quote_ident(table_schema) || '.' || quote_ident(table_name), 'select')
         AND has_schema_privilege(table_schema, 'usage')
         """