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Mathematical Functions and Operators

Numeric Operators

  • +

    Description: Addition

    Example:

    mogdb=# SELECT 2+3 AS RESULT;
     result 
    --------
          5
    (1 row)
  • -

    Description: Subtraction

    Example:

    mogdb=# SELECT 2-3 AS RESULT;
     result 
    --------
         -1
    (1 row)
  • *

    Description: Multiplication

    Example:

    mogdb=# SELECT 2*3 AS RESULT;
     result 
    --------
          6
    (1 row)
  • /

    Description: Division (The result is not rounded.)

    Example:

    mogdb=# SELECT 4/2 AS RESULT;
     result 
    --------
          2
    (1 row)
    mogdb=# SELECT 4/3 AS RESULT;
          result      
    ------------------
     1.33333333333333
    (1 row)
  • +/-

    Description: Positive/negative

    Example:

    mogdb=# SELECT -2 AS RESULT;
     result 
    --------
         -2
    (1 row)
  • %

    Description: Model (to obtain the remainder)

    Example:

    mogdb=# SELECT 5%4 AS RESULT;
     result 
    --------
          1
    (1 row)
  • @

    Description: Absolute value

    Example:

    mogdb=# SELECT @ -5.0 AS RESULT;
     result 
    --------
        5.0
    (1 row)
  • ^

    Description: Power (exponent calculation)

    Example:

    mogdb=# SELECT 2.0^3.0 AS RESULT;
           result       
    --------------------
     8.0000000000000000
    (1 row)
  • |/

    Description: Square root

    Example:

    mogdb=# SELECT |/ 25.0 AS RESULT;
     result 
    --------
          5
    (1 row)
  • ||/

    Description: Cubic root

    Example:

    mogdb=# SELECT ||/ 27.0 AS RESULT;
     result 
    --------
          3
    (1 row)
  • !

    Description: Factorial

    Example:

    mogdb=# SELECT 5! AS RESULT;
     result 
    --------
        120
    (1 row)
  • !!

    Description: Factorial (prefix operator)

    Example:

    mogdb=# SELECT !!5 AS RESULT;
     result 
    --------
        120
    (1 row)
  • &

    Description: Binary AND

    Example:

    mogdb=# SELECT 91&15  AS RESULT;
     result 
    --------
         11
    (1 row)
  • |

    Description: Binary OR

    Example:

    mogdb=# SELECT 32|3  AS RESULT;
     result 
    --------
         35
    (1 row)
  • #

    Description: Binary XOR

    Example:

    mogdb=# SELECT 17#5  AS RESULT;
     result 
    --------
         20
    (1 row)
  • ~

    Description: Binary NOT

    Example:

    mogdb=# SELECT ~1 AS RESULT;
     result 
    --------
         -2
    (1 row)
  • <<

    Description: Binary shift left

    Example:

    mogdb=# SELECT 1<<4 AS RESULT;
     result 
    --------
         16
    (1 row)
  • >>

    Description: Binary shift right

    Example:

    mogdb=# SELECT 8>>2 AS RESULT;
     result 
    --------
          2
    (1 row)

Numeric Operation Functions

  • abs(x)

    Description: Absolute value

    Return type: same as the input

    Example:

    mogdb=# SELECT abs(-17.4);
     abs
    ------
     17.4
    (1 row)
  • acos(x)

    Description: Arc cosine

    Return type: double precision

    Example:

    mogdb=# SELECT acos(-1);
           acos       
    ------------------
     3.14159265358979
    (1 row)
  • asin(x)

    Description: Arc sine

    Return type: double precision

    Example:

    mogdb=# SELECT asin(0.5);
           asin       
    ------------------
     .523598775598299
    (1 row)
  • atan(x)

    Description: Arc tangent

    Return type: double precision

    Example:

    mogdb=# SELECT atan(1);
           atan       
    ------------------
     .785398163397448
    (1 row)
  • atan2(y, x)

    Description: Arc tangent of y/x

    Return type: double precision

    Example:

    mogdb=# SELECT atan2(2, 1);
          atan2
    ------------------
     1.10714871779409
    (1 row)
  • bitand(integer, integer)

    Description: Performs AND (&) operation on two integers.

    Return type: bigint

    Example:

    mogdb=# SELECT bitand(127, 63);
     bitand 
    --------
         63
    (1 row)
  • cbrt(dp)

    Description: Cubic root

    Return type: double precision

    Example:

    mogdb=# SELECT cbrt(27.0);
     cbrt
    ------
        3
    (1 row)
  • ceil(x)

    Description: Minimum integer greater than or equal to the parameter

    Return type: integer

    Example:

    mogdb=# SELECT ceil(-42.8);
     ceil 
    ------
      -42
    (1 row)
  • ceiling(dp or numeric)

    Description: Minimum integer (alias of ceil) greater than or equal to the parameter

    Return type: same as the input

    Example:

    mogdb=# SELECT ceiling(-95.3);
     ceiling
    ---------
         -95
    (1 row)
  • cos(x)

    Description: Cosine

    Return type: double precision

    Example:

    mogdb=# SELECT cos(-3.1415927);
            cos        
    -------------------
     -.999999999999999
    (1 row)
  • cot(x)

    Description: Cotangent

    Return type: double precision

    Example:

    mogdb=# SELECT cot(1);
           cot
    ------------------
     .642092615934331
    (1 row)
  • degrees(dp)

    Description: Converts radians to angles.

    Return type: double precision

    Example:

    mogdb=# SELECT degrees(0.5);
         degrees
    ------------------
     28.6478897565412
    (1 row)
  • div(y numeric, x numeric)

    Description: Integer part of y/x

    Return type: numeric

    Example:

    mogdb=# SELECT div(9,4);
     div
    -----
       2
    (1 row)
  • exp(x)

    Description: Natural exponent

    Return type: same as the input

    Example:

    mogdb=# SELECT exp(1.0);
            exp         
    --------------------
     2.7182818284590452
    (1 row)
  • floor(x)

    Description: Not larger than the maximum integer of the parameter

    Return type: same as the input

    Example:

    mogdb=# SELECT floor(-42.8);
     floor 
    -------
       -43
    (1 row)
  • int1(in)

    Description: Converts the input text parameter to the int1-type value and returns the value.

    Return type: int1

    Example:

    mogdb=# select int1('123');
     int1
    ------
     123
    (1 row)
    mogdb=# select int1('a');
     int1
    ------
       0
    (1 row)
  • int2(in)

    Description: Converts the input parameter to the int2-type value and returns the value.

    The input parameter type supported includes float4, float8, numeric and text.

    Return type: int2

    Example:

    mogdb=# select int2('1234');
     int2
    ------
     1234
    (1 row)
    mogdb=# select int2(25.3);
     int2
    ------
       25
    (1 row)
  • int4(in)

    Description: Converts the input parameter to the int4-type value and returns the value.

    The input parameter type supported includes bit, boolean, char, duoble precision, numeric, real, smallint and text.

    Return type: int4

    Example:

    mogdb=# select int4('789');
     int4
    ------
     789
    (1 row)
    mogdb=# select int4(99.9);
     int4
    ------
       99
    (1 row)
  • radians(dp)

    Description: Converts angles to radians.

    Return type: double precision

    Example:

    mogdb=# SELECT radians(45.0);
         radians
    ------------------
     .785398163397448
    (1 row)
  • random()

    Description: Random number between 0.0 and 1.0

    Return type: double precision

    Example:

    mogdb=# SELECT random();
          random
    ------------------
     .824823560658842
    (1 row)
  • multiply(x double precision or text, y double precision or text)

    Description: Specifies the product of x and y.

    Return type: double precision

    Example:

    mogdb=# SELECT multiply(9.0, '3.0');
         multiply         
    -------------------
                   27
    (1 row)
    mogdb=# SELECT multiply('9.0', 3.0);
         multiply         
    -------------------
                   27
    (1 row)
  • ln(x)

    Description: Natural logarithm

    Return type: same as the input

    Example:

    mogdb=# SELECT ln(2.0);
            ln         
    -------------------
     .6931471805599453
    (1 row)
  • log(x)

    Description: Logarithm with 10 as the base

    Return type: same as the input

    Example:

    mogdb=# SELECT log(100.0);
            log         
    --------------------
     2.0000000000000000
    (1 row)
  • log(b numeric, x numeric)

    Description: Logarithm with b as the base

    Return type: numeric

    Example:

    mogdb=# SELECT log(2.0, 64.0);
            log         
    --------------------
     6.0000000000000000
    (1 row)
  • mod(x,y)

    Description: Remainder of x/y (model) If x equals to 0, 0 is returned.

    Return type: same as the parameter type

    Example:

    mogdb=# SELECT mod(9,4);
     mod 
    -----
       1
    (1 row)
    mogdb=# SELECT mod(9,0);
     mod 
    -----
       9
    (1 row)
  • pi()

    Description: π constant value

    Return type: double precision

    Example:

    mogdb=# SELECT pi();
            pi
    ------------------
     3.14159265358979
    (1 row)
  • power(a double precision, b double precision)

    Description: b power of a

    Return type: double precision

    Example:

    mogdb=# SELECT power(9.0, 3.0);
            power         
    ----------------------
     729.0000000000000000
    (1 row)
  • round(x)

    Description: Integer closest to the input parameter

    Return type: same as the input

    Example:

    mogdb=# SELECT round(42.4);
     round 
    -------
        42
    (1 row)
        
    mogdb=# SELECT round(42.6);
     round 
    -------
        43
    (1 row)
  • round(v numeric, s int)

    Description:s digits are kept after the decimal point.

    Return type: numeric

    Example:

    mogdb=# SELECT round(42.4382, 2);
     round
    -------
     42.44
    (1 row)
  • setseed(dp)

    Description: Sets seed for the following random() invoking (between -1.0 and 1.0, inclusive).

    Return type: void

    Example:

    mogdb=# SELECT setseed(0.54823);
     setseed
    ---------
        
    (1 row)
  • sign(x)

    Description: returns symbols of this parameter.

    The return value type:-1 indicates negative. 0 indicates 0, and 1 indicates a positive number.

    Example:

    mogdb=# SELECT sign(-8.4);
     sign 
    ------
       -1
    (1 row)
  • sin(x)

    Description: Sine

    Return type: double precision

    Example:

    mogdb=# SELECT sin(1.57079);
           sin        
    ------------------
     .999999999979986
    (1 row)
  • sqrt(x)

    Description: Square root

    Return type: same as the input

    Example:

    mogdb=# SELECT sqrt(2.0);
           sqrt        
    -------------------
     1.414213562373095
    (1 row)
  • tan(x)

    Description: Tangent

    Return type: double precision

    Example:

    mogdb=# SELECT tan(20);
           tan        
    ------------------
     2.23716094422474
    (1 row)
  • trunc(x)

    Description: truncates (the integral part).

    Return type: same as the input

    Example:

    mogdb=# SELECT trunc(42.8);
     trunc 
    -------
        42
    (1 row)
  • trunc(v numeric, s int)

    Description: Truncates a number with s digits after the decimal point.

    Return type: numeric

    Example:

    mogdb=# SELECT trunc(42.4382, 2);
     trunc
    -------
     42.43
    (1 row)
  • smgrne(a smgr, b smgr)

    Description: Compares whether two smgr-type integers are not equal.

    Return type: bool

  • smgreq(a smgr, b smgr)

    Description: Compares whether two smgr-type integers are equal.

    Return type: bool

  • width_bucket(op numeric, b1 numeric, b2 numeric, count int)

    Description: Returns a bucket to which the operand will be assigned in an equi-depth histogram with count buckets, ranging from b1 to b2.

    Return type: int

    Example:

    mogdb=# SELECT width_bucket(5.35, 0.024, 10.06, 5);
     width_bucket
    --------------
                3
    (1 row)
  • width_bucket(op dp, b1 dp, b2 dp, count int)

    Description: Returns a bucket to which the operand will be assigned in an equi-depth histogram with count buckets, ranging from b1 to b2.

    Return type: int

    Example:

    mogdb=# SELECT width_bucket(5.35, 0.024, 10.06, 5);
     width_bucket
    --------------
                3
    (1 row)