MAKEDATE(year,dayofyear)

返回的日期，給定年份和天 - 年值。 dayofyear必須大於0，否則結果為NULL。

mysql> SELECT MAKEDATE(2001,31), MAKEDATE(2001,32);
+---------------------------------------------------------+
| MAKEDATE(2001,31), MAKEDATE(2001,32)                    |
+---------------------------------------------------------+
| '2001-01-31', '2001-02-01'                              |
+---------------------------------------------------------+
1 row in set (0.00 sec)