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Hive UDF collates string function numeric string length function: length

Syntax: length (string A)

Return value: int

Description: returns the length of string A

For example:

Hive > select length ('abcedfg') from dual

seven

String inversion function: reverse

Syntax: reverse (string A)

Return value: string

Description: returns the inversion result of the string A

For example:

Hive > select reverse ('abcedfg') from dual

Gfdecba

String concatenation function: concat

Syntax: concat (string A, string B...)

Return value: string

Description: returns the result of the input string connection. Any input string is supported.

For example:

Hive > select concat ('abc','def','gh') from dual

Abcdefgh

Delimited string concatenation function: concat_ws

Syntax: concat_ws (string SEP, string A, string B...)

Return value: string

Description: returns the result after the input string is concatenated. SEP represents the delimiter between each string.

For example:

Hive > select concat_ws (',', 'abc','def','gh') from dual

Abc,def,gh

String interception function: substr,substring

Syntax: substr (string A, int start), substring (string A, int start)

Return value: string

Description: returns the string A from the start position to the end of the string

For example:

Hive > select substr ('abcde',3) from dual

Cde

Hive > select substring ('abcde',3) from dual

Cde

Hive > select substr ('abcde',-1) from dual; (same as ORACLE)

E

String interception function: substr,substring

Syntax: substr (string A, int start, int len), substring (string A, int start, int len)

Return value: string

Description: returns the string A that starts at the start position and has a length of len.

For example:

Hive > select substr ('abcde',3,2) from dual

Cd

Hive > select substring ('abcde',3,2) from dual

Cd

Hive > select substring ('abcde',-2,2) from dual

De

String to uppercase function: upper,ucase

Syntax: upper (string A) ucase (string A)

Return value: string

Description: returns the uppercase format of string A

For example:

Hive > select upper ('abSEd') from dual

ABSED

Hive > select ucase ('abSEd') from dual

ABSED

String to lowercase function: lower,lcase

Syntax: lower (string A) lcase (string A)

Return value: string

Description: returns the lowercase format of string A

For example:

Hive > select lower ('abSEd') from dual

Absed

Hive > select lcase ('abSEd') from dual

Absed

Unspace function: trim

Syntax: trim (string A)

Return value: string

Description: remove spaces on both sides of the string

For example:

Hive > select trim ('abc') from dual

Abc

Go to the left space function: ltrim

Syntax: ltrim (string A)

Return value: string

Description: remove the space on the left side of the string

For example:

Hive > select ltrim ('abc') from dual

Abc

The right-hand space function: rtrim

Syntax: rtrim (string A)

Return value: string

Description: remove the space on the right side of the string

For example:

Hive > select rtrim ('abc') from dual

Abc

Regular expression replacement function: regexp_replace

Syntax: regexp_replace (string A, string B, string C)

Return value: string

Description: replace the part of the string A that conforms to the java regular expression B with C. Note that escape characters are used in some cases

For example:

Hive > select regexp_replace ('foobar',' oo | ar', ") from dual

Fb

Regular expression parsing function: regexp_extract

Syntax: regexp_extract (string subject, string pattern, int index)

Return value: string

Description: splits the string subject according to the rules of pattern regular expressions and returns the characters specified by index. Note that escape characters are used in some cases

For example:

Hive > select regexp_extract ('foothebar',' foo (. *?) (bar)', 1) from dual

The

Hive > select regexp_extract ('foothebar',' foo (. *?) (bar)', 2) from dual

Bar

Hive > select regexp_extract ('foothebar',' foo (. *?) (bar)', 0) from dual

Foothebar

URL analytic function: parse_url

Syntax: parse_url (string urlString, string partToExtract [, string keyToExtract])

Return value: string

Description: returns the specified part of the URL. The valid values of partToExtract are: HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, and USERINFO.

For example:

Hive > select parse_url ('http://facebook.com/path2/p.php?k1=v1&k2=v2#Ref1 boys,' HOST') from dual

Facebook.com

Hive > select parse_url ('http://facebook.com/path2/p.php?k1=v1&k2=v2#Ref1 boys,' QUERY', 'K1') from dual

V1

Json analytic function: get_json_object

Syntax: get_json_object (string json_string, string path)

Return value: string

Description: parses the string json_string of json and returns the content specified by path. If the json string entered is not valid, NULL is returned.

For example:

Hive > select get_json_object ('{"store":

> {"fruit":\ [{"weight": 8, "type": "apple"}, {"weight": 9, "type": "pear"}]

> "bicycle": {"price": 19.95, "color": "red"}

>}

> "email": "amy@only_for_json_udf_test.net"

> "owner": "amy"

>}

>','$.owner') from dual

Amy

Space string function: space

Syntax: space (int n)

Return value: string

Description: returns a string of length n

For example:

Hive > select space (10) from dual

Hive > select length (space (10)) from dual

ten

Repeating string function: repeat

Syntax: repeat (string str, int n)

Return value: string

Description: returns the str string repeated n times

For example:

Hive > select repeat ('abc',5) from dual

Abcabcabcabcabc

First character ascii function: ascii

Syntax: ascii (string str)

Return value: int

Description: returns the ascii code of the first character of the string str

For example:

Hive > select ascii ('abcde') from dual

ninety-seven

Left complement function: lpad

Syntax: lpad (string str, int len, string pad)

Return value: string

Description: use pad to complete str to Lenn bit

For example:

Hive > select lpad ('abc',10,'td') from dual

Tdtdtdtabc

Unlike GP,ORACLE, pad cannot default

Right complement function: rpad

Syntax: rpad (string str, int len, string pad)

Return value: string

Description: right complement of str to Lenn bit with pad

For example:

Hive > select rpad ('abc',10,'td') from dual

Abctdtdtdt

Split string function: split

Syntax: split (string str, string pat)

Return value: array

Note: split the str according to the pat string and return the split string array.

For example:

Hive > select split ('abtcdtef','t') from dual

["ab", "cd", "ef"]

Collection lookup function: find_in_set

Syntax: find_in_set (string str, string strList)

Return value: int

Description: returns the position where str first appeared in strlist. Strlist is a string separated by commas. If the str character is not found, 0 is returned (can only be separated by commas, otherwise 0 is returned)

For example:

Hive > select find_in_set ('ab','ef,ab,de') from dual

two

Hive > select find_in_set ('at','ef,ab,de') from dual

0

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