算数运算符和函数
大约 3 分钟
算数运算符和函数
算数运算符
一元算数运算符
支持的运算符：+, -
输入数据类型要求：INT32, INT64, FLOAT, DOUBLE
输出数据类型：与输入数据类型一致
二元算数运算符
支持的运算符：+, -, *, /, %
输入数据类型要求：INT32, INT64, FLOAT和DOUBLE
输出数据类型：DOUBLE
注意：当某个时间戳下左操作数和右操作数都不为空（null）时，二元运算操作才会有输出结果
使用示例
例如：
select s1, - s1, s2, + s2, s1 + s2, s1 - s2, s1 * s2, s1 / s2, s1 % s2 from root.sg.d1
结果：
+-----------------------------+-------------+--------------+-------------+-------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+
| Time|root.sg.d1.s1|-root.sg.d1.s1|root.sg.d1.s2|root.sg.d1.s2|root.sg.d1.s1 + root.sg.d1.s2|root.sg.d1.s1 - root.sg.d1.s2|root.sg.d1.s1 * root.sg.d1.s2|root.sg.d1.s1 / root.sg.d1.s2|root.sg.d1.s1 % root.sg.d1.s2|
+-----------------------------+-------------+--------------+-------------+-------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+
|1970-01-01T08:00:00.001+08:00| 1.0| -1.0| 1.0| 1.0| 2.0| 0.0| 1.0| 1.0| 0.0|
|1970-01-01T08:00:00.002+08:00| 2.0| -2.0| 2.0| 2.0| 4.0| 0.0| 4.0| 1.0| 0.0|
|1970-01-01T08:00:00.003+08:00| 3.0| -3.0| 3.0| 3.0| 6.0| 0.0| 9.0| 1.0| 0.0|
|1970-01-01T08:00:00.004+08:00| 4.0| -4.0| 4.0| 4.0| 8.0| 0.0| 16.0| 1.0| 0.0|
|1970-01-01T08:00:00.005+08:00| 5.0| -5.0| 5.0| 5.0| 10.0| 0.0| 25.0| 1.0| 0.0|
+-----------------------------+-------------+--------------+-------------+-------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+
Total line number = 5
It costs 0.014s
数学函数
目前 IoTDB 支持下列数学函数，这些数学函数的行为与这些函数在 Java Math 标准库中对应实现的行为一致。
| 函数名 | 输入序列类型 | 输出序列类型 | 必要属性参数 | Java 标准库中的对应实现 |
|---|---|---|---|---|
| SIN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#sin(double) | |
| COS | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#cos(double) | |
| TAN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#tan(double) | |
| ASIN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#asin(double) | |
| ACOS | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#acos(double) | |
| ATAN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#atan(double) | |
| SINH | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#sinh(double) | |
| COSH | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#cosh(double) | |
| TANH | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#tanh(double) | |
| DEGREES | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#toDegrees(double) | |
| RADIANS | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#toRadians(double) | |
| ABS | INT32 / INT64 / FLOAT / DOUBLE | 与输入序列的实际类型一致 | Math#abs(int) / Math#abs(long) /Math#abs(float) /Math#abs(double) | |
| SIGN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#signum(double) | |
| CEIL | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#ceil(double) | |
| FLOOR | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#floor(double) | |
| ROUND | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | places:四舍五入有效位数，正数为小数点后面的有效位数，负数为整数位的有效位数 | Math#rint(Math#pow(10,places))/Math#pow(10,places) |
| EXP | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#exp(double) | |
| LN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#log(double) | |
| LOG10 | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#log10(double) | |
| SQRT | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#sqrt(double) |
例如：
select s1, sin(s1), cos(s1), tan(s1) from root.sg1.d1 limit 5 offset 1000;
结果：
+-----------------------------+-------------------+-------------------+--------------------+-------------------+
| Time| root.sg1.d1.s1|sin(root.sg1.d1.s1)| cos(root.sg1.d1.s1)|tan(root.sg1.d1.s1)|
+-----------------------------+-------------------+-------------------+--------------------+-------------------+
|2020-12-10T17:11:49.037+08:00|7360723084922759782| 0.8133527237573284| 0.5817708713544664| 1.3980636773094157|
|2020-12-10T17:11:49.038+08:00|4377791063319964531|-0.8938962705202537| 0.4482738644511651| -1.994085181866842|
|2020-12-10T17:11:49.039+08:00|7972485567734642915| 0.9627757585308978|-0.27030138509681073|-3.5618602479083545|
|2020-12-10T17:11:49.040+08:00|2508858212791964081|-0.6073417341629443| -0.7944406950452296| 0.7644897069734913|
|2020-12-10T17:11:49.041+08:00|2817297431185141819|-0.8419358900502509| -0.5395775727782725| 1.5603611649667768|
+-----------------------------+-------------------+-------------------+--------------------+-------------------+
Total line number = 5
It costs 0.008s
ROUND
例如：
select s4,round(s4),round(s4,2),round(s4,-1) from root.sg1.d1
+-----------------------------+-------------+--------------------+----------------------+-----------------------+
| Time|root.db.d1.s4|ROUND(root.db.d1.s4)|ROUND(root.db.d1.s4,2)|ROUND(root.db.d1.s4,-1)|
+-----------------------------+-------------+--------------------+----------------------+-----------------------+
|1970-01-01T08:00:00.001+08:00| 101.14345| 101.0| 101.14| 100.0|
|1970-01-01T08:00:00.002+08:00| 20.144346| 20.0| 20.14| 20.0|
|1970-01-01T08:00:00.003+08:00| 20.614372| 21.0| 20.61| 20.0|
|1970-01-01T08:00:00.005+08:00| 20.814346| 21.0| 20.81| 20.0|
|1970-01-01T08:00:00.006+08:00| 60.71443| 61.0| 60.71| 60.0|
|2023-03-13T16:16:19.764+08:00| 10.143425| 10.0| 10.14| 10.0|
+-----------------------------+-------------+--------------------+----------------------+-----------------------+
Total line number = 6
It costs 0.059s