give bigquery list_schemas/check_schema_exist macros

plugins/bigquery/dbt/adapters/bigquery/impl.py

@@ -75,6 +75,7 @@ def rename_relation(self, from_relation, to_relation):
             '`rename_relation` is not implemented for this adapter!'
         )
 
+    @available
     def list_schemas(self, database):
         conn = self.connections.get_thread_connection()
         client = conn.handle
@@ -84,6 +85,11 @@ def list_schemas(self, database):
                                                 include_all=True)
             return [ds.dataset_id for ds in all_datasets]
 
+    @available
+    def check_schema_exists(self, database, schema):
+        superself = super(BigQueryAdapter, self)
+        return superself.check_schema_exists(database, schema)
+
     def get_columns_in_relation(self, relation):
         try:
             table = self.connections.get_bq_table(

plugins/bigquery/dbt/include/bigquery/macros/adapters.sql

@@ -67,3 +67,13 @@
 {% macro bigquery__current_timestamp() -%}
   CURRENT_TIMESTAMP()
 {%- endmacro %}
+
+
+{% macro bigquery__list_schemas(database) %}
+  {{ return(adapter.list_schemas()) }}
+{% endmacro %}
+
+
+{% macro bigquery__check_schema_exists(database, schema) %}
+  {{ return(adapter.check_schema_exists(database, schema)) }}
+{% endmacro %}