fix(bigframes): escape backtick in ordering_clause identifier

Author: Samin061

packages/bigframes/bigframes/core/sql/__init__.py

@@ -154,7 +154,7 @@ def ordering_clause(
             # Probably shouldn't have constants in ordering definition, but best to ignore if somehow they end up here.
             continue
         assert isinstance(ordering_expr, bigframes.core.expression.DerefOp)
-        part = f"`{ordering_expr.id.sql}` {asc_desc} {null_clause}"
+        part = f"`{escape_chars(ordering_expr.id.sql)}` {asc_desc} {null_clause}"
         parts.append(part)
     return f"ORDER BY {' ,'.join(parts)}"
 

packages/bigframes/tests/unit/core/test_sql.py

@@ -12,9 +12,24 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import bigframes.core.expression as ex
+import bigframes.core.identifiers as ids
+import bigframes.core.ordering as order
 from bigframes.core import sql
 
 
+def test_ordering_clause_escapes_backtick_in_column_name():
+    ordering = order.OrderingExpression(ex.DerefOp(ids.ColumnId("col`,(SELECT 1))--")))
+    result = sql.ordering_clause([ordering])
+    assert result == "ORDER BY `col\\`,(SELECT 1))--` ASC NULLS LAST"
+
+
+def test_ordering_clause_leaves_plain_column_name_unchanged():
+    ordering = order.OrderingExpression(ex.DerefOp(ids.ColumnId("my_col")))
+    result = sql.ordering_clause([ordering])
+    assert result == "ORDER BY `my_col` ASC NULLS LAST"
+
+
 def test_create_vector_search_sql_simple():
     result_query = sql.create_vector_search_sql(
         sql_string="SELECT embedding FROM my_embeddings_table WHERE id = 1",