Engine-specific rendering for sub-daily granularity options

metricflow/protocols/sql_client.py

@@ -2,8 +2,10 @@
 
 from abc import abstractmethod
 from enum import Enum
-from typing import Protocol
+from typing import Protocol, Set
 
+from dbt_semantic_interfaces.enum_extension import assert_values_exhausted
+from dbt_semantic_interfaces.type_enums.time_granularity import TimeGranularity
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 
 from metricflow.data_table.mf_table import MetricFlowDataTable
@@ -24,6 +26,26 @@ class SqlEngine(Enum):
     DATABRICKS = "Databricks"
     TRINO = "Trino"
 
+    @property
+    def unsupported_granularities(self) -> Set[TimeGranularity]:
+        """Granularities that can't be used with this SqlEngine."""
+        if self is SqlEngine.SNOWFLAKE:
+            return set()
+        elif self is SqlEngine.BIGQUERY:
+            return {TimeGranularity.NANOSECOND}
+        elif self is SqlEngine.DATABRICKS:
+            return {TimeGranularity.NANOSECOND}
+        elif self is SqlEngine.DUCKDB:
+            return {TimeGranularity.NANOSECOND}
+        elif self is SqlEngine.POSTGRES:
+            return {TimeGranularity.NANOSECOND}
+        elif self is SqlEngine.REDSHIFT:
+            return {TimeGranularity.NANOSECOND}
+        elif self is SqlEngine.TRINO:
+            return {TimeGranularity.NANOSECOND, TimeGranularity.MICROSECOND}
+        else:
+            assert_values_exhausted(self)
+
 
 class SqlClient(Protocol):
     """Base interface for SqlClient instances used inside MetricFlow.

metricflow/sql/render/big_query.py

@@ -10,6 +10,7 @@
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -31,6 +32,8 @@
 class BigQuerySqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the BigQuery engine."""
 
+    sql_engine = SqlEngine.BIGQUERY
+
     @property
     @override
     def double_data_type(self) -> str:
@@ -120,14 +123,18 @@ def visit_cast_to_timestamp_expr(self, node: SqlCastToTimestampExpression) -> Sq
     @override
     def visit_date_trunc_expr(self, node: SqlDateTruncExpression) -> SqlExpressionRenderResult:
         """Render DATE_TRUNC for BigQuery, which takes the opposite argument order from Snowflake and Redshift."""
+        self._validate_granularity_for_engine(node.time_granularity)
+
         arg_rendered = self.render_sql_expr(node.arg)
 
         prefix = ""
         if node.time_granularity == TimeGranularity.WEEK:
             prefix = "iso"
 
+        trunc_expr = "DATE_TRUNC" if node.time_granularity.to_int() >= TimeGranularity.DAY.to_int() else "TIME_TRUNC"
+
         return SqlExpressionRenderResult(
-            sql=f"DATE_TRUNC({arg_rendered.sql}, {prefix}{node.time_granularity.value})",
+            sql=f"{trunc_expr}({arg_rendered.sql}, {prefix}{node.time_granularity.value})",
             bind_parameters=arg_rendered.bind_parameters,
         )
 

metricflow/sql/render/databricks.py

@@ -7,6 +7,7 @@
 from metricflow_semantics.errors.error_classes import UnsupportedEngineFeatureError
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -19,6 +20,8 @@
 class DatabricksSqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the Databricks engine."""
 
+    sql_engine = SqlEngine.DATABRICKS
+
     @property
     @override
     def supported_percentile_function_types(self) -> Collection[SqlPercentileFunctionType]:

metricflow/sql/render/duckdb_renderer.py

@@ -7,6 +7,7 @@
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -24,6 +25,8 @@
 class DuckDbSqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the DuckDB engine."""
 
+    sql_engine = SqlEngine.DUCKDB
+
     @property
     @override
     def supported_percentile_function_types(self) -> Collection[SqlPercentileFunctionType]:

metricflow/sql/render/expr_renderer.py

@@ -5,7 +5,7 @@
 from abc import ABC, abstractmethod
 from collections import namedtuple
 from dataclasses import dataclass
-from typing import Collection, List
+from typing import TYPE_CHECKING, Collection, List, Optional
 
 import jinja2
 from dbt_semantic_interfaces.type_enums.date_part import DatePart
@@ -41,6 +41,10 @@
 )
 from metricflow.sql.sql_plan import SqlSelectColumn
 
+if TYPE_CHECKING:
+    from metricflow.protocols.sql_client import SqlEngine
+
+
 logger = logging.getLogger(__name__)
 
 
@@ -93,6 +97,10 @@ def can_render_percentile_function(self, percentile_type: SqlPercentileFunctionT
 class DefaultSqlExpressionRenderer(SqlExpressionRenderer):
     """Renders the SQL query plan assuming ANSI SQL."""
 
+    @property
+    def sql_engine(self) -> Optional[SqlEngine]:  # noqa: D102
+        return None
+
     @property
     @override
     def double_data_type(self) -> str:
@@ -263,7 +271,13 @@ def visit_cast_to_timestamp_expr(  # noqa: D102
             bind_parameters=arg_rendered.bind_parameters,
         )
 
+    def _validate_granularity_for_engine(self, time_granularity: TimeGranularity) -> None:
+        if self.sql_engine and time_granularity in self.sql_engine.unsupported_granularities:
+            raise RuntimeError(f"{self.sql_engine.name} does not support time granularity {time_granularity.name}.")
+
     def visit_date_trunc_expr(self, node: SqlDateTruncExpression) -> SqlExpressionRenderResult:  # noqa: D102
+        self._validate_granularity_for_engine(node.time_granularity)
+
         arg_rendered = self.render_sql_expr(node.arg)
 
         return SqlExpressionRenderResult(

metricflow/sql/render/postgres.py

@@ -8,6 +8,7 @@
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -25,6 +26,8 @@
 class PostgresSqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the PostgreSQL engine."""
 
+    sql_engine = SqlEngine.POSTGRES
+
     @property
     @override
     def double_data_type(self) -> str:

metricflow/sql/render/redshift.py

@@ -8,6 +8,7 @@
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -25,6 +26,8 @@
 class RedshiftSqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the Redshift engine."""
 
+    sql_engine = SqlEngine.REDSHIFT
+
     @property
     @override
     def double_data_type(self) -> str:

metricflow/sql/render/snowflake.py

@@ -8,6 +8,7 @@
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -24,6 +25,8 @@
 class SnowflakeSqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the Snowflake engine."""
 
+    sql_engine = SqlEngine.SNOWFLAKE
+
     @property
     @override
     def supported_percentile_function_types(self) -> Collection[SqlPercentileFunctionType]:

metricflow/sql/render/trino.py

@@ -9,6 +9,7 @@
 from metricflow_semantics.sql.sql_bind_parameters import SqlBindParameters
 from typing_extensions import override
 
+from metricflow.protocols.sql_client import SqlEngine
 from metricflow.sql.render.expr_renderer import (
     DefaultSqlExpressionRenderer,
     SqlExpressionRenderer,
@@ -27,6 +28,8 @@
 class TrinoSqlExpressionRenderer(DefaultSqlExpressionRenderer):
     """Expression renderer for the Trino engine."""
 
+    sql_engine = SqlEngine.TRINO
+
     @property
     @override
     def supported_percentile_function_types(self) -> Collection[SqlPercentileFunctionType]: