WIP

metricflow-semantics/metricflow_semantics/dag/id_prefix.py

@@ -56,6 +56,7 @@ class StaticIdPrefix(IdPrefix, Enum, metaclass=EnumMetaClassHelper):
     DATAFLOW_NODE_JOIN_CONVERSION_EVENTS_PREFIX = "jce"
     DATAFLOW_NODE_WINDOW_REAGGREGATION_ID_PREFIX = "wr"
     DATAFLOW_NODE_ALIAS_SPECS_ID_PREFIX = "as"
+    DATAFLOW_NODE_CUSTOM_GRANULARITY_BOUNDS_ID_PREFIX = "cgb"
 
     SQL_EXPR_COLUMN_REFERENCE_ID_PREFIX = "cr"
     SQL_EXPR_COMPARISON_ID_PREFIX = "cmp"
@@ -75,6 +76,7 @@ class StaticIdPrefix(IdPrefix, Enum, metaclass=EnumMetaClassHelper):
     SQL_EXPR_BETWEEN_PREFIX = "betw"
     SQL_EXPR_WINDOW_FUNCTION_ID_PREFIX = "wfnc"
     SQL_EXPR_GENERATE_UUID_PREFIX = "uuid"
+    SQL_EXPR_CASE_PREFIX = "case"
 
     SQL_PLAN_SELECT_STATEMENT_ID_PREFIX = "ss"
     SQL_PLAN_TABLE_FROM_CLAUSE_ID_PREFIX = "tfc"

metricflow-semantics/metricflow_semantics/instances.py

@@ -164,11 +164,7 @@ def with_entity_prefix(
     ) -> TimeDimensionInstance:
         """Returns a new instance with the entity prefix added to the entity links."""
         transformed_spec = self.spec.with_entity_prefix(entity_prefix)
-        return TimeDimensionInstance(
-            associated_columns=(column_association_resolver.resolve_spec(transformed_spec),),
-            defined_from=self.defined_from,
-            spec=transformed_spec,
-        )
+        return self.with_new_spec(transformed_spec, column_association_resolver)
 
     def with_new_defined_from(self, defined_from: Sequence[SemanticModelElementReference]) -> TimeDimensionInstance:
         """Returns a new instance with the defined_from field replaced."""

metricflow-semantics/metricflow_semantics/specs/time_dimension_spec.py

@@ -15,6 +15,7 @@
 from metricflow_semantics.naming.linkable_spec_name import StructuredLinkableSpecName
 from metricflow_semantics.specs.dimension_spec import DimensionSpec
 from metricflow_semantics.specs.instance_spec import InstanceSpecVisitor
+from metricflow_semantics.sql.sql_exprs import SqlWindowFunction
 from metricflow_semantics.time.granularity import ExpandedTimeGranularity
 from metricflow_semantics.visitor import VisitorOutputT
 
@@ -91,6 +92,8 @@ class TimeDimensionSpec(DimensionSpec):  # noqa: D101
     # Used for semi-additive joins. Some more thought is needed, but this may be useful in InstanceSpec.
     aggregation_state: Optional[AggregationState] = None
 
+    window_function: Optional[SqlWindowFunction] = None
+
     @property
     def without_first_entity_link(self) -> TimeDimensionSpec:  # noqa: D102
         assert len(self.entity_links) > 0, f"Spec does not have any entity links: {self}"
@@ -99,6 +102,8 @@ def without_first_entity_link(self) -> TimeDimensionSpec:  # noqa: D102
             entity_links=self.entity_links[1:],
             time_granularity=self.time_granularity,
             date_part=self.date_part,
+            aggregation_state=self.aggregation_state,
+            window_function=self.window_function,
         )
 
     @property
@@ -108,6 +113,8 @@ def without_entity_links(self) -> TimeDimensionSpec:  # noqa: D102
             time_granularity=self.time_granularity,
             date_part=self.date_part,
             entity_links=(),
+            aggregation_state=self.aggregation_state,
+            window_function=self.window_function,
         )
 
     @property
@@ -153,6 +160,7 @@ def with_grain(self, time_granularity: ExpandedTimeGranularity) -> TimeDimension
             time_granularity=time_granularity,
             date_part=self.date_part,
             aggregation_state=self.aggregation_state,
+            window_function=self.window_function,
         )
 
     def with_base_grain(self) -> TimeDimensionSpec:  # noqa: D102
@@ -162,6 +170,7 @@ def with_base_grain(self) -> TimeDimensionSpec:  # noqa: D102
             time_granularity=ExpandedTimeGranularity.from_time_granularity(self.time_granularity.base_granularity),
             date_part=self.date_part,
             aggregation_state=self.aggregation_state,
+            window_function=self.window_function,
         )
 
     def with_grain_and_date_part(  # noqa: D102
@@ -173,6 +182,7 @@ def with_grain_and_date_part(  # noqa: D102
             time_granularity=time_granularity,
             date_part=date_part,
             aggregation_state=self.aggregation_state,
+            window_function=self.window_function,
         )
 
     def with_aggregation_state(self, aggregation_state: AggregationState) -> TimeDimensionSpec:  # noqa: D102
@@ -182,6 +192,17 @@ def with_aggregation_state(self, aggregation_state: AggregationState) -> TimeDim
             time_granularity=self.time_granularity,
             date_part=self.date_part,
             aggregation_state=aggregation_state,
+            window_function=self.window_function,
+        )
+
+    def with_window_function(self, window_function: SqlWindowFunction) -> TimeDimensionSpec:  # noqa: D102
+        return TimeDimensionSpec(
+            element_name=self.element_name,
+            entity_links=self.entity_links,
+            time_granularity=self.time_granularity,
+            date_part=self.date_part,
+            aggregation_state=self.aggregation_state,
+            window_function=window_function,
         )
 
     def comparison_key(self, exclude_fields: Sequence[TimeDimensionSpecField] = ()) -> TimeDimensionSpecComparisonKey:
@@ -243,6 +264,7 @@ def with_entity_prefix(self, entity_prefix: EntityReference) -> TimeDimensionSpe
             time_granularity=self.time_granularity,
             date_part=self.date_part,
             aggregation_state=self.aggregation_state,
+            window_function=self.window_function,
         )
 
     @staticmethod

metricflow-semantics/metricflow_semantics/sql/sql_exprs.py

@@ -15,11 +15,12 @@
 from dbt_semantic_interfaces.type_enums.date_part import DatePart
 from dbt_semantic_interfaces.type_enums.period_agg import PeriodAggregation
 from dbt_semantic_interfaces.type_enums.time_granularity import TimeGranularity
+from typing_extensions import override
+
 from metricflow_semantics.dag.id_prefix import IdPrefix, StaticIdPrefix
 from metricflow_semantics.dag.mf_dag import DagNode, DisplayedProperty
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameterSet
 from metricflow_semantics.visitor import Visitable, VisitorOutputT
-from typing_extensions import override
 
 
 @dataclass(frozen=True, eq=False)
@@ -235,6 +236,10 @@ def visit_window_function_expr(self, node: SqlWindowFunctionExpression) -> Visit
     def visit_generate_uuid_expr(self, node: SqlGenerateUuidExpression) -> VisitorOutputT:  # noqa: D102
         pass
 
+    @abstractmethod
+    def visit_case_expr(self, node: SqlCaseExpression) -> VisitorOutputT:  # noqa: D102
+        pass
+
 
 @dataclass(frozen=True, eq=False)
 class SqlStringExpression(SqlExpressionNode):
@@ -948,11 +953,18 @@ class SqlWindowFunction(Enum):
     FIRST_VALUE = "FIRST_VALUE"
     LAST_VALUE = "LAST_VALUE"
     AVERAGE = "AVG"
+    ROW_NUMBER = "ROW_NUMBER"
+    LAG = "LAG"
 
     @property
     def requires_ordering(self) -> bool:
         """Asserts whether or not ordering the window function will have an impact on the resulting value."""
-        if self is SqlWindowFunction.FIRST_VALUE or self is SqlWindowFunction.LAST_VALUE:
+        if (
+            self is SqlWindowFunction.FIRST_VALUE
+            or self is SqlWindowFunction.LAST_VALUE
+            or self is SqlWindowFunction.ROW_NUMBER
+            or self is SqlWindowFunction.LAG
+        ):
             return True
         elif self is SqlWindowFunction.AVERAGE:
             return False
@@ -1715,3 +1727,67 @@ def lineage(self) -> SqlExpressionTreeLineage:  # noqa: D102
 
     def matches(self, other: SqlExpressionNode) -> bool:  # noqa: D102
         return False
+
+
+@dataclass(frozen=True, eq=False)
+class SqlCaseExpression(SqlExpressionNode):
+    """Renders a CASE WHEN expression."""
+
+    when_to_then_exprs: Dict[SqlExpressionNode, SqlExpressionNode]
+    else_expr: Optional[SqlExpressionNode]
+
+    @staticmethod
+    def create(  # noqa: D102
+        when_to_then_exprs: Dict[SqlExpressionNode, SqlExpressionNode], else_expr: Optional[SqlExpressionNode] = None
+    ) -> SqlCaseExpression:
+        parent_nodes: Tuple[SqlExpressionNode, ...] = ()
+        for when, then in when_to_then_exprs.items():
+            parent_nodes += (when,)
+            parent_nodes += (then,)
+
+        if else_expr:
+            parent_nodes += (else_expr,)
+
+        return SqlCaseExpression(parent_nodes=parent_nodes, when_to_then_exprs=when_to_then_exprs, else_expr=else_expr)
+
+    @classmethod
+    def id_prefix(cls) -> IdPrefix:  # noqa: D102
+        return StaticIdPrefix.SQL_EXPR_CASE_PREFIX
+
+    def accept(self, visitor: SqlExpressionNodeVisitor[VisitorOutputT]) -> VisitorOutputT:  # noqa: D102
+        return visitor.visit_case_expr(self)
+
+    @property
+    def description(self) -> str:  # noqa: D102
+        return "Case expression"
+
+    @property
+    def displayed_properties(self) -> Sequence[DisplayedProperty]:  # noqa: D102
+        return super().displayed_properties
+
+    @property
+    def requires_parenthesis(self) -> bool:  # noqa: D102
+        return False
+
+    @property
+    def bind_parameter_set(self) -> SqlBindParameterSet:  # noqa: D102
+        return SqlBindParameterSet()
+
+    def __repr__(self) -> str:  # noqa: D105
+        return f"{self.__class__.__name__}(node_id={self.node_id})"
+
+    def rewrite(  # noqa: D102
+        self,
+        column_replacements: Optional[SqlColumnReplacements] = None,
+        should_render_table_alias: Optional[bool] = None,
+    ) -> SqlExpressionNode:
+        return self
+
+    @property
+    def lineage(self) -> SqlExpressionTreeLineage:  # noqa: D102
+        return SqlExpressionTreeLineage(other_exprs=(self,))
+
+    def matches(self, other: SqlExpressionNode) -> bool:  # noqa: D102
+        if not isinstance(other, SqlCaseExpression):
+            return False
+        return self.when_to_then_exprs == other.when_to_then_exprs and self.else_expr == other.else_expr

metricflow-semantics/metricflow_semantics/test_helpers/semantic_manifest_yamls/simple_manifest/metrics.yaml

@@ -860,3 +860,24 @@ metric:
       - name: instant_bookings
         alias: shared_alias
 ---
+metric:
+  name: bookings_offset_one_martian_day
+  description: bookings offset by one martian_day
+  type: derived
+  type_params:
+    expr: bookings
+    metrics:
+      - name: bookings
+        offset_window: 1 martian_day
+---
+metric:
+  name: bookings_martian_day_over_martian_day
+  description: bookings growth martian day over martian day
+  type: derived
+  type_params:
+    expr: bookings - bookings_offset / NULLIF(bookings_offset, 0)
+    metrics:
+      - name: bookings
+        offset_window: 1 martian_day
+        alias: bookings_offset
+      - name: bookings

metricflow-semantics/tests_metricflow_semantics/collection_helpers/test_pretty_print.py

@@ -47,6 +47,7 @@ def test_classes() -> None:  # noqa: D103
               time_granularity=ExpandedTimeGranularity(name='day', base_granularity=DAY),
               date_part=None,
               aggregation_state=None,
+              window_function=None,
             )
             """
         ).rstrip()