函数名 |
函数解释 |
函数举例 |
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AVG() |
返回一组数值的平均值. |
SELECT AVG(SALARY ) FROM BSEMPMS; |
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CORR(),CORRELATION() |
返回一对数值的关系系数. |
SELECT CORRELATION(SALARY,BONUS) FROM BSEMPMS; |
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COUNT() |
返回一组行或值的个数. |
SELECT COUNT(*) FROM BSEMPMS; |
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COVAR(),COVARIANCE() |
返回一对数值的协方差. |
SELECT COVAR(SALARY,BONUS) FROM BSEMPMS; |
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MAX() |
返回一组数值中的最大值. |
SELECT MAX(SALARY) FROM BSEMPMS; |
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MIN() |
返回一组数值中的最小值. |
SELECT MIN(SALARY) FROM BSEMPMS; |
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STDDEV() |
返回一组数值的标准偏差. |
SELECT STDDEV(SALARY) FROM BSEMPMS; |
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SUM() |
返回一组数据的和. |
SELECT SUM(SALARY) FROM BSEMPMS; |
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VAR(),VARIANCE() |
返回一组数值的方差. |
SELECT VARIANCE(SALARY) FROM BSEMPMS; |
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ABS(),ABSVAL() |
返回参数的绝对值. |
SELECT ABS(-3.4) FROM BSEMPMS; |
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ACOS() |
返回参数的反余弦值. |
SELECT ACOS(0.9) FROM BSEMPMS; |
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ASCII() |
返回整数参数最左边的字符的ASCII码. |
SELECT ASCII('R') FROM BSEMPMS; |
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ASIN() |
返回用弧度表示的角度的参数的反正弦函数. |
SELECT ASIN(0.9) FROM BSEMPMS; |
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ATAN() |
返回参数的反正切值,该参数用弧度表示的角度的参数. |
SELECT ATAN(0.9) FROM BSEMPMS; |
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ATAN2() |
返回用弧度表示的角度的X和Y坐标的反正切值. |
SELECT ATAN2(0.5,0.9) FROM BSEMPMS; |
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BIGINT() |
返回整型常量中的数字或字符串的64位整数表示. |
SELECT BIGINT(EMP_NO) FROM BSEMPMS; |
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CEILING() OR CELL() |
返回比参数大或等于参数的最小的整数值. |
SELECT CEILING(3.56) FROM BSEMPMS;SELECT CEIL(4.67) FROM BSEMPMS; |
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CHAR() |
返回日期时间型,字符串,整数,十进制或双精度浮点数的字符串表示. |
SELECT CHAR(SALARY,',') FROM BSEMPMS; |
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CHR() |
返回具有由参数指定的ASCII码的字符. |
SELECT CHAR(167) FROM BSEMPMS; |
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CONCAT() |
返回两个字符串的连接. |
SELECT CONCAT(EMP_NO,EMP_NAM) FROM BSEMPMS; |
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YEAR() |
返回数值的年部分. |
SELECT YEAR('2003/01/02') FROM BSEMPMS; |
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VARCHAR() |
返回字符串,日期型,图形串的可变长度的字符串表示. |
SELECT VARCHAR(EMP_NAM,50) FROM BSEMPMS; |
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UCASE() OR UPPER() |
返回字符串的大写. |
SELECT UCASE(EMP_NAM) FROM BSEMPMS;SELECT UPPER(EMP_NO) FROM BSEMPMS; |
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TRUNCATE() OR TRUNC() |
从表达式小数点右边的位置开始截断并返回该数值. |
SELECT TRUNCATE(345.6789,2) FROM BSEMPMS; |
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TIME() |
返回一个数值中的时间. |
SELECT TIME('2001-03-19.12.30.123456') FROM BSEMPMS; |
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SUBSTR(EXP1,EXP2) |
返回EXP1串自EXP2处开始的子串. |
SELECT SUBSTR('CDNJFDJFJD',5) FROM BSEMPMS;SELECT SUBSTR('CDNJFDJFJD',5,2) FROM BSEMPMS; |
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SQRT() |
返回该参数的平方根. |
SELECT SQRT(36) FROM BSEMPMS; |
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SPACE() |
返回由参数指定的长度,包含空格在内的字符串. |
SELECT SPACE(10) FROM BSEMPMS; |
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SECOND() |
返回一个数值的秒部分. |
SELECT SECOND('18:34:32') FROM BSEMPMS; |
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RTRIM() |
删除字符串尾部的空格. |
SELECT RTRIM('COMMENT') FROM BSEMPMS; |
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ROUND(EXP1,EXP2) |
返回EXP1小数点右边的第EXP2位置处开始的四舍五入值. |
SELECT ROUND(2345.6789,2) FROM BSEMPMS |
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REPLACE(EXP1,EXP2,EXP3) |
用EXP3替代EXP1中所有的EXP2 |
SELECT CHAR(REPLACE('ROMANDD','NDD','CCB'),10) FROM BSEMPMS; |
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REPEAT(EXP1,EXP2) |
返回EXP1重复EXP2次后的字符串. |
SELECT CHAR(REPEAT('REPEAT',3),21) FROM BSEMPMS; |
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REAL() |
返回一个数值的单精度浮点数表示. |
SELECT REAL(10) FROM BSEMPMS; |
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RAND() |
返回0和1之间的随机浮点数. |
SELECT RAND() FROM BSEMPMS; |
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POWER(EXP1,EXP2) |
返回EXP1的EXP2次幂. |
SELECT POWER(2,5) FROM BSEMPMS; |
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POSSTR(EXP1,EXP2) |
返回EXP2在EXP1中的位置. |
SELECT ('ABCDEFGH','D') FROM BSEMPMS; |
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NULLIF(EXP1,EXP2) |
如果EXP1=EXP2,则为NULL,否则为EXP1 |
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NODENUMBER() |
返回行的分区号. |
SELECT NODENUMBER(EMP_NO) FROM BSEMPMS; |
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MONTH() |
返回一个数值的月部分. |
SELECT MONTH('2003/10/20') FROM BSEMPMS; |
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MOD(EXP1,EXP2) |
返回EXP1除以EXP2的余数. |
SELECT MOD(20,8) FROM BSEMPMS; |
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MINUTE() |
返回一个数值的分钟部分. |
SELECT MINUTE('18:34:23') FROM BSEMPMS; |
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LTRIM() |
删除字符串前面的空格. |
SELECT LTRIM('CDDD') FROM BSEMPMS; |
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HOUR() |
返回一个数值的小时部分. |
SELECT HOUR('18:34:23') FROM BSEMPMS; |
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DOUBLE() |
如果参数是一个数字表达式,返回与其相对应的浮点数,如果参数是字符串表达式,则返回该数的字符串表达式. |
SELECT DOUBLE('5678') FROM BSEMPMS; |
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EXP() |
返回参数的指数函数. |
SELECT EXP(2) FROM BSEMPMS; |
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FLOAT() |
返回一个数的浮点表示. |
SELECT FLOAT(789) FROM BSEMPMS; |
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FLOOR() |
返回小于或等于参数的最大整数. |
SELECT FLOOR(88.93) FROM BSEMPMS; |
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HEX() |
返回一个表示为字符串的值的16进制表示. |
SELECT HEX(16) FROM BSEMPMS; |