Merge pull request #375 from motherduckdb/guenp/delete-temp-table-if-…

…exists

Add pre-model hook for cleaning up remote temporary table on MotherDuck

dbt/adapters/duckdb/impl.py

@@ -241,11 +241,23 @@ def render_column_constraint(cls, constraint: ColumnLevelConstraint) -> Optional
         else:
             return super().render_column_constraint(constraint)
 
+    def _clean_up_temp_relation_for_incremental(self, config):
+        if self.is_motherduck():
+            if "incremental" == config.model.get_materialization():
+                temp_relation = self.Relation(
+                    path=self.get_temp_relation_path(config.model), type=RelationType.Table
+                )
+                self.drop_relation(temp_relation)
+
     def pre_model_hook(self, config: Any) -> None:
-        """A hook for getting the temp schema name from the model config"""
+        """A hook for getting the temp schema name from the model config.
+        Cleans up the remote temporary table on MotherDuck before running
+        an incremental model.
+        """
         self._temp_schema_name = config.model.config.meta.get(
             TEMP_SCHEMA_NAME, self._temp_schema_name
         )
+        self._clean_up_temp_relation_for_incremental(config)
         super().pre_model_hook(config)
 
     @available
@@ -262,12 +274,7 @@ def post_model_hook(self, config: Any, context: Any) -> None:
         """A hook for cleaning up the remote temporary table on MotherDuck if the
         incremental model materialization fails to do so.
         """
-        if self.is_motherduck():
-            if "incremental" == config.model.get_materialization():
-                temp_relation = self.Relation(
-                    path=self.get_temp_relation_path(config.model), type=RelationType.Table
-                )
-                self.drop_relation(temp_relation)
+        self._clean_up_temp_relation_for_incremental(config)
         super().post_model_hook(config, context)
 
 

tests/functional/plugins/test_motherduck.py

@@ -109,6 +109,11 @@ def test_incremental(self, project):
         res = project.run_sql("SELECT schema_name FROM information_schema.schemata WHERE catalog_name = 'test'", fetch="all")
         assert "dbt_temp_test" in [_r for (_r,) in res]
 
+    def test_incremental_temp_table_exists(self, project):
+        project.run_sql('create or replace table test.dbt_temp_test.summary_of_logs_test as (select 1 from generate_series(1,10) g(x))')
+        run_dbt()
+        res = project.run_sql("SELECT count(*) FROM summary_of_logs_test", fetch="one")
+        assert res == (70,)
 
 @pytest.fixture
 def mock_md_plugin():