如果數據庫時間字段的類型是datetime 跟TIMESTAMP ，則mybatis中的jdbctype都是TIMESTAMP
| MySQL Type Name | Return value of GetColumnClassName | Returned as Java Class |
| DATETIME | DATETIME | java.sql.Timestamp |
| DATE | DATE | java.sql.Date |
| TIMESTAMP[(M)] | TIMESTAMP | java.sql.Timestamp |
| TIME | TIME | java.sql.Time |