算术运算符
StoneDB的算术运算符有如下。
运算符 | 作用 |
---|---|
+ | 加 |
- | 减 |
* | 乘 |
/(或div) | 除 |
%(mod) | 取模 |
> select 10+2 from dual;
+------+
| 10+2 |
+------+
| 12 |
+------+
1 row in set (0.00 sec)
> select 10-2 from dual;
+------+
| 10-2 |
+------+
| 8 |
+------+
1 row in set (0.00 sec)
> select 10*2 from dual;
+------+
| 10*2 |
+------+
| 20 |
+------+
1 row in set (0.00 sec)
> select 10/2 from dual;
+--------+
| 10/2 |
+--------+
| 5.0000 |
+--------+
1 row in set (0.00 sec)
> select 10 div 2 from dual;
+----------+
| 10 div 2 |
+----------+
| 5 |
+----------+
1 row in set (0.00 sec)
> select 10 mod 3 from dual;
+----------+
| 10 mod 3 |
+----------+
| 1 |
+----------+
1 row in set (0.00 sec)
> select 10 % 3 from dual;
+--------+
| 10 % 3 |
+--------+
| 1 |
+--------+
1 row in set (0.00 sec)
> select 10 mod 0 from dual;
+----------+
| 10 mod 0 |
+----------+
| NULL |
+----------+
1 row in set (0.00 sec)
> select 10 / 0 from dual;
+--------+
| 10 / 0 |
+--------+
| NULL |
+--------+
1 row in set (0.00 sec)
注:在除法运算和模运算中,如果除数为0,将是非法除数,返回结果为NULL。