Shulou(Shulou.com)06/01 Report--

This article mainly introduces "the grammar and usage of numeric functions in hive". In daily operation, I believe that many people have doubts about the grammar and usage of numeric functions in hive. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "the grammar and usage of numeric functions in hive". Next, please follow the editor to study!

1. Take the whole function: round

Syntax: round (double a)

Return value: BIGINT

Description: returns the integer value part of the double type (following rounding)

For example:

Hive > select round (3.1415926) from lxw_dual

three

Hive > select round (3.5) from lxw_dual

four

Hive > create table lxw_dual as select round (9542.158) fromlxw_dual

Hive > describe lxw_dual

_ c0 bigint

two。 Specified precision integer function: round

Syntax: round (double a, int d)

Return value: DOUBLE

Description: returns the double type of the specified precision d

For example:

Hive > select round (3.1415926) from lxw_dual

3.1416

3. Take the whole function down: floor

Syntax: floor (double a)

Return value: BIGINT

Description: returns the largest integer equal to or less than the double variable

For example:

Hive > select floor (3.1415926) from lxw_dual

three

Hive > select floor (25) from lxw_dual

twenty-five

4. Take the whole function up: ceil

Syntax: ceil (double a)

Return value: BIGINT

Description: returns the smallest integer equal to or greater than the double variable

For example:

Hive > select ceil (3.1415926) from lxw_dual

four

Hive > select ceil (46) from lxw_dual

forty-six

5. Take the whole function up: ceiling

Syntax: ceiling (double a)

Return value: BIGINT

Description: same function as ceil

For example:

Hive > select ceiling (3.1415926) from lxw_dual

four

Hive > select ceiling (46) from lxw_dual

forty-six

6. Take random number function: rand

Syntax: rand (), rand (int seed)

Return value: double

Description: returns a random number in the range of 0 to 1. If you specify a seed seed, you will wait for a stable sequence of random numbers

For example:

Hive > select rand () from lxw_dual

0.5577432776034763

Hive > select rand () from lxw_dual

0.6638336467363424

Hive > select rand (100) from lxw_dual

0.7220096548596434

Hive > select rand (100) from lxw_dual

0.7220096548596434

7. Natural exponential function: exp

Syntax: exp (double a)

Return value: double

Description: returns the a power of the natural logarithm e

For example:

Hive > select exp (2) from lxw_dual

7.38905609893065

Natural logarithmic function: ln

Syntax: ln (double a)

Return value: double

Description: returns the natural logarithm of a

For example:

Hive > select ln (7.38905609893065) from lxw_dual

2.0

8. Logarithmic function with base 10: log10

Syntax: log10 (double a)

Return value: double

Description: returns the logarithm of a with a base of 10

For example:

Hive > select log10 (100) from lxw_dual

2.0

9. Logarithmic function with base 2: log2

Syntax: log2 (double a)

Return value: double

Description: returns the logarithm of a with base 2

For example:

Hive > select log2 (8) from lxw_dual

3.0

10. Logarithmic function: log

Syntax: log (double base, double a)

Return value: double

Description: returns the logarithm of a with base as the base

For example:

Hive > select log (4256) from lxw_dual

4.0

11. Exponentiation function: pow

Syntax: pow (double a, double p)

Return value: double

Description: returns the p power of a

For example:

Hive > select pow (2pr 4) from lxw_dual

16.0

twelve。 Exponentiation function: power

Syntax: power (double a, double p)

Return value: double

Description: returns the p power of a, which has the same function as pow

For example:

Hive > select power (2pr 4) from lxw_dual

16.0

13. Square function: sqrt

Syntax: sqrt (double a)

Return value: double

Description: returns the square root of a

For example:

Hive > select sqrt (16) from lxw_dual

4.0

14. Binary function: bin

Syntax: bin (BIGINT a)

Return value: string

Description: returns the binary representation of a

For example:

Hive > select bin (7) from lxw_dual

one hundred and eleven

15. Hexadecimal function: hex

Syntax: hex (BIGINT a)

Return value: string

Description: returns the hexadecimal representation of an if the variable is of type int; if the variable is of type string, the hexadecimal representation of the string

For example:

Hive > select hex (17) from lxw_dual

eleven

Hive > select hex ('abc') from lxw_dual

616263

16. Reverse hexadecimal function: unhex

Syntax: unhex (string a)

Return value: string

Description: returns the string coded by the hexadecimal string

For example:

Hive > select unhex ('616263') from lxw_dual

Abc

Hive > select unhex ('11') from lxw_dual

-

Hive > select unhex (616263) from lxw_dual

Abc

17. Binary conversion function: conv

Syntax: conv (BIGINT num, int from_base, int to_base)

Return value: string

Description: convert the numeric num from from_base to to_base

For example:

Hive > select conv (17, 10, 16) from lxw_dual

eleven

Hive > select conv (170.10jue 2) from lxw_dual

10001

18. Absolute value function: abs

Syntax: abs (double a) abs (int a)

Return value: double int

Description: returns the absolute value of the value a

For example:

Hive > select abs (- 3.9) from lxw_dual

3.9

Hive > select abs (10.9) from lxw_dual

10.9

19. Positive remainder function: pmod

Syntax: pmod (int a, int b), pmod (double a, double b)

Return value: int double

Description: returns the remainder of positive a divided by b

For example:

Hive > select pmod (9. 4) from lxw_dual

one

Hive > select pmod (- 9pm 4) from lxw_dual

three

20. Sine function: sin

Syntax: sin (double a)

Return value: double

Description: returns the sine of a

For example:

Hive > select sin (0.8) from lxw_dual

0.7173560908995228

21. Arcsine function: asin

Syntax: asin (double a)

Return value: double

Description: returns the arcsine of a

For example:

Hive > select asin (0.7173560908995228) from lxw_dual

0.8

twenty-two。 CoSine function: cos

Syntax: cos (double a)

Return value: double

Description: returns the cosine of a

For example:

Hive > select cos (0.9) from lxw_dual

0.6216099682706644

23. Inverse cosine function: acos

Syntax: acos (double a)

Return value: double

Description: returns the inverse cosine of a

For example:

Hive > select acos (0.6216099682706644) from lxw_dual

0.9

24. Positive function: positive

Syntax: positive (int a), positive (double a)

Return value: int double

Description: return a

For example:

Hive > select positive (- 10) from lxw_dual

-10

Hive > select positive (12) from lxw_dual

twelve

25. Negative function: negative

Syntax: negative (int a), negative (double a)

Return value: int double

Description: return-a

For example:

Hive > select negative (- 5) from lxw_dual

five

Hive > select negative (8) from lxw_dual

At this point, the study of "the grammar and usage of numeric functions in hive" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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