Fix Incorrect Column Name Rendering For WhereConstraintNode

.changes/unreleased/Fixes-20231128-142315.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: Fix Incorrect SQL Column Name Rendering for WhereConstraintNode
+time: 2023-11-28T14:23:15.269611-08:00
+custom:
+  Author: plypaul
+  Issue: "908"

metricflow/plan_conversion/dataflow_to_sql.py

@@ -755,8 +755,12 @@ def visit_pass_elements_filter_node(self, node: FilterElementsNode) -> SqlDataSe
 
     def visit_where_constraint_node(self, node: WhereConstraintNode) -> SqlDataSet:
         """Adds where clause to SQL statement from parent node."""
-        from_data_set: SqlDataSet = node.parent_node.accept(self)
-        output_instance_set = from_data_set.instance_set
+        parent_data_set: SqlDataSet = node.parent_node.accept(self)
+        # Since we're copying the instance set from the parent to conveniently generate the output instance set for this
+        # node, we'll need to change the column names.
+        output_instance_set = parent_data_set.instance_set.transform(
+            ChangeAssociatedColumns(self._column_association_resolver)
+        )
         from_data_set_alias = self._next_unique_table_alias()
 
         column_associations_in_where_sql: Sequence[ColumnAssociation] = CreateColumnAssociations(
@@ -771,7 +775,7 @@ def visit_where_constraint_node(self, node: WhereConstraintNode) -> SqlDataSet:
                 select_columns=output_instance_set.transform(
                     CreateSelectColumnsForInstances(from_data_set_alias, self._column_association_resolver)
                 ).as_tuple(),
-                from_source=from_data_set.sql_select_node,
+                from_source=parent_data_set.sql_select_node,
                 from_source_alias=from_data_set_alias,
                 joins_descs=(),
                 group_bys=(),

metricflow/plan_conversion/instance_converters.py

@@ -845,7 +845,34 @@ def transform(self, instance_set: InstanceSet) -> SelectColumnSet:  # noqa: D
 
 
 class ChangeAssociatedColumns(InstanceSetTransform[InstanceSet]):
-    """Change the columns associated with instances to the one specified by the resolver."""
+    """Change the columns associated with instances to the one specified by the resolver.
+
+    This is useful for conveniently generating output instances for a node that serve as a "pass-through". The output
+    instances can be a copy of the parent's instances, except that the column names need to be changed.
+
+    e.g. the parent may have a data set:
+        sql:
+            SELECT
+                is_lux AS is_lux_latext
+            ...
+        instance:
+            DimensionInstance(column_name="is_lux", ...)
+
+    but for the current node, we want a data set like:
+
+        sql:
+            SELECT
+                is_lux_latest
+                ...
+            FROM (
+                -- SQL from parent
+                is_lux AS is_lux_latest
+                ...
+            )
+            ...
+        instance:
+            DimensionInstance(column_name="is_lux_latest")
+    """
 
     def __init__(self, column_association_resolver: ColumnAssociationResolver) -> None:  # noqa: D
         self._column_association_resolver = column_association_resolver

metricflow/test/plan_conversion/dataflow_to_sql/test_distinct_values_to_sql.py

@@ -0,0 +1,79 @@
+from __future__ import annotations
+
+import pytest
+from _pytest.fixtures import FixtureRequest
+from dbt_semantic_interfaces.implementations.filters.where_filter import PydanticWhereFilter
+from dbt_semantic_interfaces.references import EntityReference
+
+from metricflow.dataflow.builder.dataflow_plan_builder import DataflowPlanBuilder
+from metricflow.plan_conversion.dataflow_to_sql import DataflowToSqlQueryPlanConverter
+from metricflow.protocols.sql_client import SqlClient
+from metricflow.specs.column_assoc import ColumnAssociationResolver
+from metricflow.specs.specs import DimensionSpec, MetricFlowQuerySpec
+from metricflow.specs.where_filter_transform import WhereSpecFactory
+from metricflow.test.fixtures.setup_fixtures import MetricFlowTestSessionState
+from metricflow.test.plan_conversion.test_dataflow_to_sql_plan import convert_and_check
+
+
+@pytest.mark.sql_engine_snapshot
+def test_dimensions_requiring_join(
+    request: FixtureRequest,
+    mf_test_session_state: MetricFlowTestSessionState,
+    dataflow_plan_builder: DataflowPlanBuilder,
+    dataflow_to_sql_converter: DataflowToSqlQueryPlanConverter,
+    sql_client: SqlClient,
+) -> None:
+    """Tests querying 2 dimensions that require a join."""
+    dimension_specs = (
+        DimensionSpec(element_name="home_state_latest", entity_links=(EntityReference(element_name="user"),)),
+        DimensionSpec(element_name="is_lux_latest", entity_links=(EntityReference(element_name="listing"),)),
+    )
+    dataflow_plan = dataflow_plan_builder.build_plan_for_distinct_values(
+        query_spec=MetricFlowQuerySpec(dimension_specs=dimension_specs)
+    )
+
+    convert_and_check(
+        request=request,
+        mf_test_session_state=mf_test_session_state,
+        dataflow_to_sql_converter=dataflow_to_sql_converter,
+        sql_client=sql_client,
+        node=dataflow_plan.sink_output_nodes[0].parent_node,
+    )
+
+
+@pytest.mark.sql_engine_snapshot
+def test_dimension_values_with_a_join_and_a_filter(
+    request: FixtureRequest,
+    mf_test_session_state: MetricFlowTestSessionState,
+    column_association_resolver: ColumnAssociationResolver,
+    dataflow_plan_builder: DataflowPlanBuilder,
+    dataflow_to_sql_converter: DataflowToSqlQueryPlanConverter,
+    sql_client: SqlClient,
+) -> None:
+    """Tests querying 2 dimensions that require a join and a filter."""
+    dimension_specs = (
+        DimensionSpec(element_name="home_state_latest", entity_links=(EntityReference(element_name="user"),)),
+        DimensionSpec(element_name="is_lux_latest", entity_links=(EntityReference(element_name="listing"),)),
+    )
+    dataflow_plan = dataflow_plan_builder.build_plan_for_distinct_values(
+        query_spec=MetricFlowQuerySpec(
+            dimension_specs=dimension_specs,
+            where_constraint=(
+                WhereSpecFactory(
+                    column_association_resolver=column_association_resolver,
+                ).create_from_where_filter(
+                    PydanticWhereFilter(
+                        where_sql_template="{{ Dimension('user__home_state_latest') }} = 'us'",
+                    )
+                )
+            ),
+        )
+    )
+
+    convert_and_check(
+        request=request,
+        mf_test_session_state=mf_test_session_state,
+        dataflow_to_sql_converter=dataflow_to_sql_converter,
+        sql_client=sql_client,
+        node=dataflow_plan.sink_output_nodes[0].parent_node,
+    )

metricflow/test/plan_conversion/test_dataflow_to_sql_plan.py

@@ -1068,29 +1068,3 @@ def test_combine_output_node(  # noqa: D
         sql_client=sql_client,
         node=combine_output_node,
     )
-
-
-@pytest.mark.sql_engine_snapshot
-def test_dimensions_requiring_join(
-    request: FixtureRequest,
-    mf_test_session_state: MetricFlowTestSessionState,
-    dataflow_plan_builder: DataflowPlanBuilder,
-    dataflow_to_sql_converter: DataflowToSqlQueryPlanConverter,
-    sql_client: SqlClient,
-) -> None:
-    """Tests querying 2 dimensions that require a join."""
-    dimension_specs = (
-        DimensionSpec(element_name="home_state_latest", entity_links=(EntityReference(element_name="user"),)),
-        DimensionSpec(element_name="is_lux_latest", entity_links=(EntityReference(element_name="listing"),)),
-    )
-    dataflow_plan = dataflow_plan_builder.build_plan_for_distinct_values(
-        query_spec=MetricFlowQuerySpec(dimension_specs=dimension_specs)
-    )
-
-    convert_and_check(
-        request=request,
-        mf_test_session_state=mf_test_session_state,
-        dataflow_to_sql_converter=dataflow_to_sql_converter,
-        sql_client=sql_client,
-        node=dataflow_plan.sink_output_nodes[0].parent_node,
-    )