fix last order column only when DML

When we do not know columnInformation
values dictionary key is always null
so overwrite value Object.
Thus always values dictionary has last order column object value

To avoid user confusion, it is marked and displayed as UNKNOWN_COL.

Author: sean-k1

pymysqlreplication/row_event.py

@@ -119,7 +119,13 @@ def _read_column_data(self, cols_bitmap):
             column = self.columns[i]
             name = self.table_map[self.table_id].columns[i].name
             unsigned = self.table_map[self.table_id].columns[i].unsigned
-
+            if not name:
+                # If you are using mysql 5.7 or mysql 8, but binlog_row_metadata = "MINIMAL",
+                # we do not know the column information.
+                # If you know column information,
+                # mysql 5.7 version Users Use Under 1.0 version
+                # mysql 8.0 version Users Set binlog_row_metadata = "FULL"
+                name = "UNKNOWN_COL" + str(i)
             values[name] = self.__read_values_name(
                 column,
                 null_bitmap,