refactor: add agg_ops.ProductOp to the sqlglot compiler

Author: chelsea-lin

bigframes/core/compile/sqlglot/aggregations/unary_compiler.py

@@ -386,6 +386,17 @@ def _(
     return apply_window_if_present(sge.func("MIN", column.expr), window)
 
 
+@UNARY_OP_REGISTRATION.register(agg_ops.NuniqueOp)
+def _(
+    op: agg_ops.NuniqueOp,
+    column: typed_expr.TypedExpr,
+    window: typing.Optional[window_spec.WindowSpec] = None,
+) -> sge.Expression:
+    return apply_window_if_present(
+        sge.func("COUNT", sge.Distinct(expressions=[column.expr])), window
+    )
+
+
 @UNARY_OP_REGISTRATION.register(agg_ops.PopVarOp)
 def _(
     op: agg_ops.PopVarOp,

tests/unit/core/compile/sqlglot/aggregations/snapshots/test_unary_compiler/test_nunique/out.sql

@@ -0,0 +1,12 @@
+WITH `bfcte_0` AS (
+  SELECT
+    `int64_col`
+  FROM `bigframes-dev`.`sqlglot_test`.`scalar_types`
+), `bfcte_1` AS (
+  SELECT
+    COUNT(DISTINCT `int64_col`) AS `bfcol_1`
+  FROM `bfcte_0`
+)
+SELECT
+  `bfcol_1` AS `int64_col`
+FROM `bfcte_1`

tests/unit/core/compile/sqlglot/aggregations/test_unary_compiler.py

@@ -412,6 +412,15 @@ def test_min(scalar_types_df: bpd.DataFrame, snapshot):
     snapshot.assert_match(sql_window_partition, "window_partition_out.sql")
 
 
+def test_nunique(scalar_types_df: bpd.DataFrame, snapshot):
+    col_name = "int64_col"
+    bf_df = scalar_types_df[[col_name]]
+    agg_expr = agg_ops.NuniqueOp().as_expr(col_name)
+    sql = _apply_unary_agg_ops(bf_df, [agg_expr], [col_name])
+
+    snapshot.assert_match(sql, "out.sql")
+
+
 def test_pop_var(scalar_types_df: bpd.DataFrame, snapshot):
     col_names = ["int64_col", "bool_col"]
     bf_df = scalar_types_df[col_names]