我们可以将算术运算符（+、-、*、/）与 INTERVAL 关键字的单位值一起使用，如下 -
使用加法 (+)
mysql> Select date('2017-10-22' + INTERVAL 2+2 Year) AS 'Date After (2+2)Years';
+------------------------+
| Date After (2+2) Years |
+------------------------+
| 2021-10-22 |
+------------------------+
1 row in set (0.00 sec)使用减法 (-)
mysql> Select date('2017-10-22' + INTERVAL 2-2 Year) AS 'Date After (2-2)Years';
+------------------------+
| Date After (2-2) Years |
+------------------------+
| 2017-10-22 |
+------------------------+
1 row in set (0.00 sec)乘法的使用 (*)
mysql> Select date('2017-10-22' + INTERVAL 2*2 Year) AS 'Date After (2*2)Years';
+------------------------+
| Date After (2*2) Years |
+------------------------+
| 2021-10-22 |
+------------------------+
1 row in set (0.00 sec)使用除号 (/)
mysql> Select date('2017-10-22' + INTERVAL 2/2 Year) AS 'Date After (2/2) Years';
+------------------------+
| Date After (2/2) Years |
+------------------------+
| 2018-10-22 |
+------------------------+
1 row in set (0.00 sec) 
