check table nullity properly

Author: TrevorBergeron

bigframes/core/compile/compiled.py

@@ -166,18 +166,6 @@ def get_column_type(self, key: str) -> bigframes.dtypes.Dtype:
             bigframes.core.compile.ibis_types.ibis_dtype_to_bigframes_dtype(ibis_type),
         )
 
-    def row_count(self, name: str) -> UnorderedIR:
-        original_table = self._to_ibis_expr()
-        ibis_table = original_table.agg(
-            [
-                original_table.count().name(name),
-            ]
-        )
-        return UnorderedIR(
-            ibis_table,
-            (ibis_table[name],),
-        )
-
     def _to_ibis_expr(
         self,
         *,

bigframes/core/compile/ibis_compiler/utils.py

@@ -774,7 +774,7 @@ def over(
         @deferrable
         def bind(table):
             winfunc = rewrite_window_input(
-                node, window.bind(table) if table else window
+                node, window.bind(table) if (table is not None) else window
             )
             if winfunc == node:
                 raise com.IbisTypeError(
@@ -784,7 +784,7 @@ def bind(table):
 
         try:
             return bind(table)
-        except com.IbisInputError as e:
+        except com.IbisInputError:
             return bind(_)
 
     def isnull(self) -> ir.BooleanValue: