爱网站无法登录怎么回事,手表网,陕西省和城乡建设厅网站,门户网站网站建设绝对值函数语法格式#xff1a;ABS(X)例#xff1a;查看三个数值的绝对值#xff08;负的绝对值为它的正整数#xff0c;0的绝对值为0#xff0c;正的绝对值为它本身#xff09;。mysql select abs(2),abs(-32),abs(-0.5);
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| abs(2) |…绝对值函数语法格式ABS(X)例查看三个数值的绝对值负的绝对值为它的正整数0的绝对值为0正的绝对值为它本身。mysql select abs(2),abs(-32),abs(-0.5);
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| abs(2) | abs(-32) | abs(-0.5) |
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| 2 | 32 | 0.5 |
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1 row in set (0.01 sec)求余函数语法格式MOD(N,M), N % M, N MOD M例查看三个数值三个方法查看取余。mysql select mod(10,3),20%3,15 mod 4;
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| mod(10,3) | 20%3 | 15 mod 4 |
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| 1 | 2 | 3 |
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1 row in set (0.00 sec)获取整数的函数语法格式CEIL(X)、CEILING(x) 、FLOOR(x)例ceil和ceiling返回不小于x的最小整数floor返回不大于x的最大整数。mysql select ceil(2.1234),ceiling(3.1234),floor(4.1234);
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| ceil(2.1234) | ceiling(3.1234) | floor(4.1234) |
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| 3 | 4 | 4 |
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1 row in set (0.00 sec)获取随机数的函数语法格式RAND() 、RAND(x) 例1:rand()用于返回一个0~1之间的随机浮点数。mysql select rand(),rand();
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| rand() | rand() |
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| 0.8802711524816893 | 0.21204793100436026 |
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1 row in set (0.00 sec)
例2rand(x)用于返回一个0~1之间的浮点数x作为种子值用来产生重复序列。
mysql select rand(2),rand(2),rand(1000000);
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| rand(2) | rand(2) | rand(1000000) |
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| 0.6555866465490187 | 0.6555866465490187 | 0.2644144708890603 |
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1 row in set (0.00 sec)四舍五入的函数语法格式ROUND(x) 、ROUND(x,y) 例roundx四舍五入为整数roundxy四舍五入保留后面两位小数。mysql select round(3.512),round(4.235,2);
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| round(3.512) | round(4.235,2) |
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| 4 | 4.24 |
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1 row in set (0.00 sec)截取数值的函数语法格式TRUNCATE(x,y) 例1截取数值保留y位。mysql select truncate(2.567,2),truncate(1.99,1);
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| truncate(2.567,2) | truncate(1.99,1) |
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| 2.56 | 1.9 |
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1 row in set (0.00 sec)例2截取1234为1000截取1234为1200负数表明把右侧的数值截取为0看到下面的操作可以想到把负数改为-1可以看到多少结果为1230mysql select truncate(1234,-3),truncate(1234,-2);
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| truncate(1234,-3) | truncate(1234,-2) |
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| 1000 | 1200 |
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1 row in set (0.00 sec)符号函数语法格式SIGN(x) 例signx表示任何负数返回-10返回0任何正数返回1。mysql select sign(-123),sign(0),sign(223);
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| sign(-123) | sign(0) | sign(223) |
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| -1 | 0 | 1 |
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1 row in set (0.00 sec)幂运算函数语法格式POW(x,y) 、POWER(x,y) 例两个用处相同pow为返回2的三次方power返回3的四次方。mysql select pow(2,3),power(3,4);
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| pow(2,3) | power(3,4) |
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| 8 | 81 |
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1 row in set (0.00 sec)
