先看看刪除之前的表結構：
mysql> select * from test;
+------+--------+----------------------------------+------------+------------+------------+------------+
| t_id | t_name | t_password | t_birth | birth | birth1 | birth2 |
+------+--------+----------------------------------+------------+------------+------------+------------+
| 1 | name1 | 12345678901234567890123456789012 | NULL | 1990-01-01 | 0000-00-00 | 2013-01-01 |
| 2 | name2 | 12345678901234567890123456789012 | 2013-01-01 | NULL | 0000-00-00 | 2013-01-01 |
+------+--------+----------------------------------+------------+------------+------------+------------+
2 rows in set (0.00 sec)
執行刪除命令，使用drop關鍵字。
基本的語法為：alter table <表名> drop column <字段名>;
具體的命令如下：
mysql> alter table test drop column birth1;
Query OK, 0 rows affected (0.13 sec)
Records: 0 Duplicates: 0 Warnings: 0
看看刪除後的結果，是不是已經沒有birth1字段了？
mysql> select * from test;
+------+--------+----------------------------------+------------+------------+------------+
| t_id | t_name | t_password | t_birth | birth | birth2 |
+------+--------+----------------------------------+------------+------------+------------+
| 1 | name1 | 12345678901234567890123456789012 | NULL | 1990-01-01 | 2013-01-01 |
| 2 | name2 | 12345678901234567890123456789012 | 2013-01-01 | NULL | 2013-01-01 |
+------+--------+----------------------------------+------------+------------+------------+
2 rows in set (0.00 sec)
關於MySQL中根據生日計算年齡的SQL語句日期函數，本文就介紹這麼多，希望對大家有所幫助，謝謝！
