From 149d5ff822da3d7fda18dbed4814e0406708cf07 Mon Sep 17 00:00:00 2001
From: Huan Chen <142538604+Genesis929@users.noreply.github.com>
Date: Thu, 22 Aug 2024 15:03:56 -0700
Subject: [PATCH] fix: struct field non-nullable type issue. (#914)

* fix: struct field non-nullable type issue.

* update logic
---
 bigframes/core/compile/scalar_op_compiler.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/bigframes/core/compile/scalar_op_compiler.py b/bigframes/core/compile/scalar_op_compiler.py
index e70c49e337..4818d3ca76 100644
--- a/bigframes/core/compile/scalar_op_compiler.py
+++ b/bigframes/core/compile/scalar_op_compiler.py
@@ -754,7 +754,9 @@ def struct_field_op_impl(x: ibis_types.Value, op: ops.StructFieldOp):
         name = op.name_or_index
     else:
         name = struct_value.names[op.name_or_index]
-    return struct_value[name].name(name)
+
+    result = struct_value[name]
+    return result.cast(result.type()(nullable=True)).name(name)
 
 
 def numeric_to_datetime(x: ibis_types.Value, unit: str) -> ibis_types.TimestampValue: