MySQL将以哪种格式Year(2)或Year(4)返回从日期'0000-00-00”开始的年份值？

mysql> Select * from detail_bday;
+----+---------+------------+
| Sr | Name    | Birth_Date |
+----+---------+------------+
| 1 | Saurabh  | 1990-05-12 |
| 2 | Raman    | 1993-06-11 |
| 3 | Gaurav   | 1984-01-17 |
| 4 | Rahul    | 1993-06-11 |
| 5 | Sonia    | 1993-11-31 |
| 6 | Ram      | 0000-00-00 |
+----+---------+------------+
6 rows in set (0.00 sec)

mysql> Select Year(Birth_date) from detail_bday Where Name = 'Ram';
+------------------+
| Year(Birth_date) |
+------------------+
|                0 |
+------------------+
1 row in set (0.00 sec)