MySql numeric functions abs (N) returns the absolute value of N www.2cto.com mysql> select ABS (2);-> 2 mysql> select ABS (-32);-> 32 sign (N) returns the parameter symbol (-1, 0, or 1) mysql> select SIGN (-32);->-1 mysql> select SIGN (0 ); -> 0 mysql> select SIGN (234);-> 1 mod (N, M) modulo operation, returns the remainder of N divided by M (same as the % operator) www.2cto.com mysql> select MOD (234, 10);-> 4 mysql> select 234% 10;-> 4 mysql> select MOD ();-> 2 floor (N) returns the maximum integer of N. mysql> select FLOOR (1.23);-> 1 mysql> select FLOOR (-1.23);->-2 ceiling (N) returns the smallest integer value of N. mysql> select CEILING (1.23);-> 2 mysql> select CEILING (-1.23);->-1 round (N, D) returns the rounding value of N and retains the D-decimal places (the default value of D is 0). mysql> select ROUND (-1.23);->-1 mysql> select ROUND (-1.58 ); ->-2 mysql> select ROUND (1.58);-> 2 mysql> select ROUND (1.298, 1);-> 1.3 mysql> select ROUND (1.298, 0 ); -> 1 exp (N) returns the N power of e (base of the natural logarithm) mysql> select EXP (2);-> 7.389056 mysql> select EXP (-2 ); -> 0.135335 log (N) returns the natural logarithm of N mysql> select LOG (2);-> 0.693147 mysql> select LOG (-2);-> NULL log10 (N) returns the base-10 logarithm of N mysql> select LOG10 (2);-> 0.301030 mysql> select LOG10 (100);-> 2.000000 mysql> select LOG10 (-100 ); -> NULL pow (X, Y) or power (X, Y) returns the Y power of X mysql> select POW (4.000000);-> mysql> select POW (2, -2);-> 0.250000 sqrt (N) returns the square root of non-negative N mysql> select SQRT (4);-> 2.000000 mysql> select SQRT (20 ); -> 4.472136 pi () returns the circumference rate mysql> select PI ();-> 3.141593 cos (N) returns the cosine of N mysql> select COS (PI ()); ->-1.000000 sin (N) returns the sine of N. mysql> select SIN (PI ();-> 0.000000 tan (N) returns the tangent of N. mysql> select TAN (PI () + 1);-> 1.557408 acos (N) returns N arc cosine (N is the cosine value, in the range from-1 to 1, otherwise NULL is returned.) mysql> select ACOS (1);-> 0.000000 mysql> select ACOS (1.0001 ); -> NULL mysql> select ACOS (0);-> 1.570796 asin (N) returns N arcsin mysql> select ASIN (0.2 ); -> 0.201358 mysql> select ASIN ('foo');-> 0.000000 atan (N) returns the arc tangent value of N mysql> select ATAN (2 ); -> 1.107149 mysql> select ATAN (-2);->-1.107149 atan2 (X, Y) returns the arc tangent of two variables X and Y (similar to the arc tangent of Y/X, the symbol determines the quadrant) mysql> select ATAN ); ->-0.785398 mysql> select ATAN (PI (), 0);-> 1.570796 cot (N) returns X's cotangent mysql> select COT (12 ); ->-1.57267341 mysql> select COT (0);-> null rand () or RAND (N) returns a random floating point value ranging from 0 to 1.0 (the number N can be used as the initial value) mysql> select RAND ();-> 0.5925 mysql> select RAND (20 ); -> 0.1811 mysql> select RAND (20);-> 0.1811 mysql> select RAND ();-> 0.2079 mysql> select RAND ();-> 0.7888 degrees (N) converts N from radians to DEGREES and returns mysql> select DEGREES (PI ();-> 180.000000 radians (N) converts N from angle to radian and returns mysql> select RADIANS (90);-> 1.570796 truncate (N, D) retain the D decimal places of the number N and return mysql> select TRUNCATE (1.223, 1);-> 1.2 mysql> select TRUNCATE (1.999, 1 ); -> 1.9 mysql> select TRUNCATE (1.999, 0);-> 1 least (X, Y ,...) returns the minimum value (if the return value is used in the context of an integer (real number or size-sensitive string) or if all parameters are integers (real number or size-sensitive string), they are used as integers (real number or size-sensitive string) otherwise, the case-insensitive strings are compared.) www.2cto.com mysql> select LEAST (34.0);-> 0 mysql> select LEAST (3.0, 5.0, 767.0 ); -> 3.0 mysql> select LEAST ("B", "A", "C");-> "A" greatest (X, Y ,...) returns the maximum value (other values are the same as LEAST () mysql> select GREATEST (34.0);-> 2 mysql> select GREATEST (3.0, 5.0, 767.0 ); -& gt; 767.0 mysql & gt; select GREATEST ("B", "A", "C");-& gt; "C"