Implement relations api dp fix (#729)

* fix bq date partitioning

* fix for context vars (tmp table name)

dbt/adapters/default/impl.py

@@ -695,7 +695,7 @@ def drop_schema(cls, profile, schema, model_name=None):
     @classmethod
     def already_exists(cls, profile, schema, table, model_name=None):
         # TODO add deprecation warning
-        relation = cls.get_relation(schema=schema, identifier=table)
+        relation = cls.get_relation(profile, schema=schema, identifier=table)
         return relation is not None
 
     @classmethod

dbt/adapters/default/relation.py

@@ -127,6 +127,8 @@ def render(self):
 
                 if path_part is None:
                     continue
+                elif k == 'identifier':
+                    path_part = self.table
 
                 parts.append(
                     self.quote_if(
@@ -156,7 +158,8 @@ def create_from_node(cls, profile, node, table_name=None, **kwargs):
         return cls.create(
             database=profile.get('dbname'),
             schema=node.get('schema'),
-            identifier=table_name or node.get('name'),
+            identifier=node.get('name'),
+            table_name=table_name,
             **kwargs)
 
     @classmethod
@@ -205,7 +208,7 @@ def name(self):
     # Here for compatibility with old Relation interface
     @property
     def table(self):
-        return self._table_name
+        return self.table_name
 
     @property
     def is_table(self):

dbt/include/global_project/macros/materializations/table/bigquery_table.sql

@@ -62,7 +62,9 @@
 
   -- build model
   {% if partitions %}
-    {{ make_date_partitioned_table(model, target_relation, partitions, exists_not_as_table, verbose) }}
+    {# Create the dp-table if 1. it does not exist or 2. it existed, but we just dropped it #}
+    {%- set should_create = (old_relation is none or exists_not_as_table) -%}
+    {{ make_date_partitioned_table(model, target_relation, partitions, should_create, verbose) }}
   {% else %}
     {% call statement('main') -%}
       {{ create_table_as(False, target_relation, sql) }}