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This article introduces the relevant knowledge of "sorting out the relevant knowledge points of Mysql mathematical functions". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

All mathematical functions return NULL in the event of an error.

-

Monocular subtraction. Change the symbol of the parameter.

Mysql > select-2

Note that if this operator is used with a BIGINT, the return value is a BIGINT! This means that you should avoid using-- on integers-- that might have a value of-2 ^ 63!

ABS (X)

Returns the absolute value of X.

Mysql > select ABS (2)

-> 2

Mysql > select ABS (- 32)

-> 32

This feature can be safely used for BIGINT values.

SIGN (X)

Returns the symbol of the parameter, which is-1, 0, or 1, depending on whether X is negative, zero, or positive.

Mysql > select SIGN (- 32)

->-1

Mysql > select SIGN (0)

-> 0

Mysql > select SIGN

-> 1

MOD (NMagol M)

%

Module (similar to the% operator in C). Returns the remainder of N divided by M.

Mysql > select MOD (234,10)

-> 4

Mysql > select 253 7

-> 1

Mysql > select MOD (29Pol 9)

-> 2

This function can be safely used for BIGINT values.

FLOOR (X)

Returns the maximum integer value not greater than X.

Mysql > select FLOOR (1.23)

-> 1

Mysql > select FLOOR (- 1.23)

->-2

Notice that the return value is transformed into a BIGINT!

CEILING (X)

Returns a minimum integer value not less than X.

Mysql > select CEILING (1.23)

-> 2

Mysql > select CEILING (- 1.23)

->-1

Notice that the return value is transformed into a BIGINT!

ROUND (X)

Returns an integer rounded to the parameter X.

Mysql > select ROUND (- 1.23)

->-1

Mysql > select ROUND (- 1.58)

->-2

Mysql > select ROUND (1.58)

-> 2

Notice that the return value is transformed into a BIGINT!

ROUND (XBI D)

Returns a number where D is a decimal when the parameter X is rounded. If D is 0, there will be no decimal point or decimal part.

Mysql > select ROUND (1.298, 1)

-> 1.3

Mysql > select ROUND (1.298, 0)

-> 1

Notice that the return value is transformed into a BIGINT!

EXP (X)

Returns the X power of the value e (the base of the natural logarithm).

Mysql > select EXP (2)

-> 7.389056

Mysql > select EXP (- 2)

-> 0.135335

LOG (X)

Returns the natural logarithm of X.

Mysql > select LOG (2)

-> 0.693147

Mysql > select LOG (- 2)

-> NULL

If you want the logarithm of any base B of a number X, use the formula LOG (X) / LOG (B).

LOG10 (X)

Returns the base 10 logarithm of X.

Mysql > select LOG10 (2)

-> 0.301030

Mysql > select LOG10

-> 2.000000

Mysql > select LOG10 (- 100)

-> NULL

POW (XQuery Y)

POWER (XQuery Y)

Returns the Y power of the value X.

Mysql > select POW (2jue 2)

-> 4.000000

Mysql > select POW (2Mae Murray 2)

-> 0.250000

SQRT (X)

Returns the square root of a nonnegative number X.

Mysql > select SQRT (4)

-> 2.000000

Mysql > select SQRT (20)

-> 4.472136

PI ()

Returns the value of PI (pi).

Mysql > select PI ()

-> 3.141593

COS (X)

Returns the cosine of X, where X is given in radians.

Mysql > select COS (PI ())

->-1.000000

SIN (X)

Returns the sine of X, where X is given in radians.

Mysql > select SIN (PI ())

-> 0.000000

TAN (X)

Returns the tangent of X, where X is given in radians.

Mysql > select TAN (PI () + 1)

-> 1.557408

ACOS (X)

Returns the inverse cosine of X, that is, the cosine value is X. If X is not in the range of-1 to 1, return NULL.

Mysql > select ACOS (1)

-> 0.000000

Mysql > select ACOS (1.0001)

-> NULL

Mysql > select ACOS (0)

-> 1.570796

ASIN (X)

Returns the X arcsine value, that is, its sine value is X. L returns NULL if X is not in the range of-1 to 1.

Mysql > select ASIN (0.2)

-> 0.201358

Mysql > select ASIN ('foo')

-> 0.000000

ATAN (X)

Returns the inverse tangent of X, that is, its tangent is X.

Mysql > select ATAN (2)

-> 1.107149

Mysql > select ATAN (- 2)

->-1.107149

ATAN2 (XQuery Y)

Returns the inverse tangent of two variables X and Y. It is similar to calculating the inverse tangent of Ymax X, except that the symbols of two parameters are used to determine the quadrant of the result.

Mysql > select ATAN (- 2)

->-0.785398

Mysql > select ATAN (PI (), 0)

-> 1.570796

COT (X)

Returns the cotangent of X.

Mysql > select COT (12)

->-1.57267341

Mysql > select COT (0)

-> NULL

RAND ()

RAND (N)

Returns a random floating-point value in the range 0 to 1.0. If an integer parameter N is specified, it is used as the seed 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

You cannot use a column with the RAND () value in an ORDER BY clause, because ORDER BY will repeat the column multiple times. In MySQL3.23, however, you can do: SELECT * FROM table_name ORDER BY RAND (), which is good for getting an AND c from SELECT * FROM table1,table2 WHERE aquib

LEAST (XMagna Y...)

There are 2 and more parameters that return the smallest (minimum) parameter. Parameters are compared using the following rules:

If the return value is used in an INTEGER context, or if all parameters are integer values, they are compared as integers.

If the return values are used in a REAL context, or if all parameters are real values, they are compared as real numbers.

If any parameter is a size-sensitive string, the parameter is compared as a case-sensitive string.

In other cases, parameters are compared as case-insensitive strings.

Mysql > select LEAST (2J0)

-> 0

Mysql > select LEAST (34.0, 3.0pm, 5.0767.0)

-> 3.0

Mysql > select LEAST ("B", "A", "C")

-> A

In versions prior to MySQL 3.22.5, you could use MIN () instead of LEAST.

GREATEST (XMagna Y...)

Returns the parameter with the maximum (maximum value). Parameters are compared using the same rules as LEAST.

Mysql > select GREATEST (2J0)

-> 2

Mysql > select GREATEST (34.0, 3.0pm, 5.0767.0)

-> 767.0

Mysql > select GREATEST ("B", "A", "C")

-> "C"

In MySQL versions prior to 3.22.5, you could use MAX () instead of GREATEST.

DEGREES (X)

Returns the parameter X, which is transformed from radians to angles.

Mysql > select DEGREES (PI ())

-> 180.000000

RADIANS (X)

Returns the parameter X, which is transformed from an angle to radians.

Mysql > select RADIANS (90)

-> 1.570796

TRUNCATE (XBI D)

Returns the number X, truncated to D decimal places. If D is 0, there will be no decimal point or decimal part.

Mysql > select TRUNCATE (1.223pc1)

-> 1.2

Mysql > select TRUNCATE (1.999jue 1)

-> 1.9

Mysql > select TRUNCATE (1.999)

-> 1

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