Method replace

lib/sqlalchemy/dialects/mysql/base.py:1484–1508

(
                element: ExternallyTraversible, **kw: Any
            )

            val = on_duplicate_update[column.key]

            def replace(
                element: ExternallyTraversible, **kw: Any
            ) -> Optional[ExternallyTraversible]:
                if (
                    isinstance(element, elements.BindParameter)
                    and element.type._isnull
                ):
                    return element._with_binary_element_type(column.type)
                elif (
                    isinstance(element, elements.ColumnClause)
                    and element.table is on_duplicate.inserted_alias
                ):
                    if requires_mysql8_alias:
                        column_literal_clause = (
                            f"{_on_dup_alias_name}."
                            f"{self.preparer.quote(element.name)}"
                        )
                    else:
                        column_literal_clause = (
                            f"VALUES({self.preparer.quote(element.name)})"
                        )
                    return literal_column(column_literal_clause)
                else:
                    # element is not replaced
                    return None

            val = visitors.replacement_traverse(val, {}, replace)
            value_text = self.process(val.self_group(), use_schema=False)