MySQL數學函數簡明總結

2024-07-24 13:06:18

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這篇文章主要介紹了MySQL數學函數簡明總結,本文總結了大多數常用的MySQL數學函數,并給出了使用實例,需要的朋友可以參考下

1. ABS(x): 返回x的絕對值

復制代碼代碼如下:

		
		mysql> select ABS(1), ABS(-1), ABS(0);
		+--------+---------+--------+
		| ABS(1) | ABS(-1) | ABS(0) |
		+--------+---------+--------+
		|      1 |       1 |      0 |
		+--------+---------+--------+

2. PI(): 返回圓周率

復制代碼代碼如下:

		
		mysql> select PI();
		+----------+
		| PI()     |
		+----------+
		| 3.141593 |
		+----------+

3. SQRT(x): 返回x的平方根，要求（x為非負數，返回NULL）

復制代碼代碼如下:

		
		mysql> select SQRT(49), SQRT(0), SQRT(-49);
		+----------+---------+-----------+
		| SQRT(49) | SQRT(0) | SQRT(-49) |
		+----------+---------+-----------+
		|        7 |       0 |      NULL |
		+----------+---------+-----------+

4. MOD(x,y): 求余函數，返回x被y除后的余數；對于帶有小數部分的數據值也起作用，它返回除法運算后的精確余數。

復制代碼代碼如下:

		
		mysql> select MOD(31,8), MOD(21,-8), MOD(-7,2), MOD(-7,-2), MOD(45.5,6);
		+-----------+------------+-----------+------------+-------------+
		| MOD(31,8) | MOD(21,-8) | MOD(-7,2) | MOD(-7,-2) | MOD(45.5,6) |
		+-----------+------------+-----------+------------+-------------+
		|         7 |          5 |        -1 |         -1 |         3.5 |
		+-----------+------------+-----------+------------+-------------+

5. CEIL(X): 返回不小X的最小整數值，返回值轉為一個BIGINT.

復制代碼代碼如下:

		
		mysql> select CEIL(-3.35), CEIL(3.35);
		+-------------+------------+
		| CEIL(-3.35) | CEIL(3.35) |
		+-------------+------------+
		|          -3 |          4 |
		+-------------+------------+

6. CEILING(X): 同CEIL(X)

復制代碼代碼如下:

		
		mysql> select CEILING(-3.35), CEILING(3.35);
		+----------------+---------------+
		| CEILING(-3.35) | CEILING(3.35) |
		+----------------+---------------+
		|             -3 |             4 |
		+----------------+---------------+

7. FLOOR(X):返回不大于X的最大整數值，返回值轉為一個BIGINT.

復制代碼代碼如下:

		
		mysql> select FLOOR(-3.35), FLOOR(3.35);
		+--------------+-------------+
		| FLOOR(-3.35) | FLOOR(3.35) |
		+--------------+-------------+
		|           -4 |           3 |
		+--------------+-------------+

8. RAND()和RAND(X)

RAND(X) 返回一個隨機浮點值，范圍在０～１之間，X為整數，它被稱作種子值，用來產生重復序列。即當Ｘ值相同時，產生的隨機數也相同；

復制代碼代碼如下:

		
		mysql> select RAND(10), RAND(10), RAND(2), RAND(-2);
		+--------------------+--------------------+--------------------+--------------------+
		| RAND(10)           | RAND(10)           | RAND(2)            | RAND(-2)           |
		+--------------------+--------------------+--------------------+--------------------+
		| 0.6570515219653505 | 0.6570515219653505 | 0.6555866465490187 | 0.6548542125661431 |
		+--------------------+--------------------+--------------------+--------------------+

RAND(): 不帶參數的RAND()每次產生不同０～１之間的隨機數

復制代碼代碼如下:

		
		mysql> SELECT RAND(), RAND(), RAND();
		+--------------------+--------------------+---------------------+
		| RAND()             | RAND()             | RAND()              |
		+--------------------+--------------------+---------------------+
		| 0.6931893636409094 | 0.5147262984092592 | 0.49406343185721285 |
		+--------------------+--------------------+---------------------+

9. ROUND(X)和ROUND(X,Y): 四舍五入函數，對Ｘ值按照Ｙ進行四舍五入，Ｙ可以省略，默認值為０;若Ｙ不為０，則保留小數點后面指定Ｙ位。

復制代碼代碼如下:

mysql> select ROUND(-1.14), ROUND(-1.9), ROUND(1.14), ROUND(1.9);
+--------------+-------------+-------------+------------+
| ROUND(-1.14) | ROUND(-1.9) | ROUND(1.14) | ROUND(1.9) |
+--------------+-------------+-------------+------------+
| -1 | -2 | 1 | 2 |
+--------------+-------------+-------------+------------+

mysql> select ROUND(1.38,1), ROUND(1.38,0), ROUND(232.38,-1), ROUND(232.38,-2);
+---------------+---------------+------------------+------------------+
| ROUND(1.38,1) | ROUND(1.38,0) | ROUND(232.38,-1) | ROUND(232.38,-2) |
+---------------+---------------+------------------+------------------+
| 1.4 | 1 | 230 | 200 |
+---------------+---------------+------------------+------------------+

10. TRUNCATE(X,Y): 與ROUND(X,Y)功能類似，但不進行四舍五入，只進行截取。

復制代碼代碼如下:

		
		mysql> select TRUNCATE(1.33,1), TRUNCATE(1.99,1), TRUNCATE(1.99,0), TRUNCATE(19.99,-1);
		+------------------+------------------+------------------+--------------------+
		| TRUNCATE(1.33,1) | TRUNCATE(1.99,1) | TRUNCATE(1.99,0) | TRUNCATE(19.99,-1) |
		+------------------+------------------+------------------+--------------------+
		|              1.3 |              1.9 |                1 |                 10 |
		+------------------+------------------+------------------+--------------------+

11. SIGN(X): 返回參數Ｘ的符號，Ｘ的值為負、零或正數時返回結果依次為－１，０或１

復制代碼代碼如下:

		mysql> select SIGN(-21), SIGN(-0),SIGN(0), SIGN(0.0), SIGN(21);
		+-----------+----------+---------+-----------+----------+
		| SIGN(-21) | SIGN(-0) | SIGN(0) | SIGN(0.0) | SIGN(21) |
		+-----------+----------+---------+-----------+----------+
		|        -1 |        0 |       0 |         0 |        1 |
		+-----------+----------+---------+-----------+----------+

12. POW(X,Y), POWER(X,Y)和EXP(X)

POW(X,Y)與POWER(X,Y)功能相同，用于返回Ｘ的Ｙ次乘方的結果值

復制代碼代碼如下:

mysql> select pow(2,2), pow(2,-2), pow(-2,2), pow(-2,-2);
+----------+-----------+-----------+------------+
| pow(2,2) | pow(2,-2) | pow(-2,2) | pow(-2,-2) |
+----------+-----------+-----------+------------+
| 4 | 0.25 | 4 | 0.25 |
+----------+-----------+-----------+------------+

mysql> select power(2,2), power(2,-2), power(-2,2), power(-2,-2);
+------------+-------------+-------------+--------------+
| power(2,2) | power(2,-2) | power(-2,2) | power(-2,-2) |
+------------+-------------+-------------+--------------+
| 4 | 0.25 | 4 | 0.25 |
+------------+-------------+-------------+--------------+

EXP(X): 返回e的Ｘ乘方后的值:

復制代碼代碼如下:

		
		mysql> select EXP(3), EXP(0), EXP(-3);
		+-------------------+--------+---------------------+
		| EXP(3)            | EXP(0) | EXP(-3)             |
		+-------------------+--------+---------------------+
		| 20.08553692318767 |      1 | 0.04978706836786393 |
		+-------------------+--------+---------------------+

13. LOG(X)和LOG10(X): 對數運算函數（Ｘ必須為正數），LOG(X)-返回Ｘ的自然對數(X相對于基數e的對數)　LOG10(X)-返回x的基數為10的對數：

復制代碼代碼如下:

		
		mysql> select LOG(-3), LOG(0), LOG(3), LOG10(-100), LOG10(0), LOG10(100);
		+---------+--------+--------------------+-------------+----------+------------+
		| LOG(-3) | LOG(0) | LOG(3)             | LOG10(-100) | LOG10(0) | LOG10(100) |
		+---------+--------+--------------------+-------------+----------+------------+
		|    NULL |   NULL | 1.0986122886681098 |        NULL |     NULL |          2 |
		+---------+--------+--------------------+-------------+----------+------------+

14. RADIANS(X) 和 DEGREES(X): 角度與弧度轉換函數

復制代碼代碼如下:

		
		mysql> select RADIANS(90), RADIANS(180), DEGREES(PI()), DEGREES(PI()/2);
		+--------------------+-------------------+---------------+-----------------+
		| RADIANS(90)        | RADIANS(180)      | DEGREES(PI()) | DEGREES(PI()/2) |
		+--------------------+-------------------+---------------+-----------------+
		| 1.5707963267948966 | 3.141592653589793 |           180 |              90 |
		+--------------------+-------------------+---------------+-----------------+

15. SIN(X), ASIN(X), COS(X), ACOS(X), TAN(X), ATAN(X), COT(X)
SIN(X): 正弦函數，其中Ｘ為弧度值
ASIN(X): 反正弦函數　其中Ｘ必須在－１到１之間

COS(X): 余弦函數，其中Ｘ為弧度值
ACOS(X): 反余弦函數　其中Ｘ必須在－１到１之間
TAN(X): 正切函數，其中Ｘ為弧度值
ATAN(X): 反正切函數，ATAN(X)與TAN(X)互為反函數

COT(X):　余切函數，函數COT和TAN互為倒函數

復制代碼代碼如下:

		
		mysql> select SIGN(PI()/2),ASIN(1),COS(PI()), ACOS(-1), TAN(PI()/4), ATAN(1), COT(0.5);
		+--------------+--------------------+-----------+-------------------+--------------------+--------------------+-------------------+
		| SIGN(PI()/2) | ASIN(1)            | COS(PI()) | ACOS(-1)          | TAN(PI()/4)        | ATAN(1)            | COT(0.5)          |
		+--------------+--------------------+-----------+-------------------+--------------------+--------------------+-------------------+
		|            1 | 1.5707963267948966 |        -1 | 3.141592653589793 | 0.9999999999999999 | 0.7853981633974483 | 1.830487721712452 |
		+--------------+--------------------+-----------+-------------------+--------------------+--------------------+-------------------+

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