Hive版本: hive-1.1.0-cdh5.14.2
1. 首字符轉ascii碼函數:ascii
語法:ascii(string str)
返回值:int
描述:返回字符串str首字符的ascii編碼
0: jdbc:hive2://node03:10000> select ascii('hello') as col1, ascii('hehe') as col2, ascii('Hi') as col3;
+-------+-------+-------+--+
| col1 | col2 | col3 |
+-------+-------+-------+--+
| 104 | 104 | 72 |
+-------+-------+-------+--+
2. 字符串連接函數: concat
語法: concat(string|binary A, string|binary B…)
返回值: string
描述: 連接A,B…,可以是任意多個
0: jdbc:hive2://node03:10000> select concat('hello',' ','world');
+--------------+--+
| _c0 |
+--------------+--+
| hello world |
+--------------+--+
3. 自定義分隔符的字符串連接函數: concat_ws
語法: concat_ws(string SEP, string A, string B…)
返回值: string
描述: 以SEP爲分隔符,連接A,B…
0: jdbc:hive2://node03:10000> select concat_ws('#','welcome','to','beijing');
+---------------------+--+
| _c0 |
+---------------------+--+
| welcome#to#beijing |
+---------------------+--+
4. 自定義分隔符的字符串數組連接函數:concat_ws
語法:concat_ws(string SEP, array)
返回值: string
描述:以SEP爲分隔符,連接array中的字符串
0: jdbc:hive2://node03:10000> select concat_ws('#',array('welcome','to','beijing'));
+---------------------+--+
| _c0 |
+---------------------+--+
| welcome#to#beijing |
+---------------------+--+
5. 字符串查找函數: field
語法:field(val T,val1 T,val2 T,val3 T,…)
返回值:int
描述: 返回val在 val1,val2,val3,…出現的位置,查找不到返回0
0: jdbc:hive2://node03:10000> select field('world','say','hello','world');
+------+--+
| _c0 |
+------+--+
| 3 |
+------+--+
6. 集合查找函數: find_in_set
語法:find_in_set(string str, string strList)
返回值: int
描述: 返回str在字符串列表strList中第一次出現的位置,查找不到返回0
0: jdbc:hive2://node03:10000> select find_in_set('ab', 'abc,b,ab,c,def');
+------+--+
| _c0 |
+------+--+
| 3 |
+------+--+
7. 數字格式化函數: format_number
語法: format_number(number x, int d)
返回值: string
描述: 把數字x格式化爲逗號分隔的千分數數字(’#,###,###.##’),並保留d個小數位
0: jdbc:hive2://node03:10000> select format_number(123456789.000, 2) as col1,
. . . . . . . . . . . . . . > format_number(123456789.000, 0) as col2,
. . . . . . . . . . . . . . > format_number(123456789.000, 5) as col3;
+-----------------+--------------+--------------------+--+
| col1 | col2 | col3 |
+-----------------+--------------+--------------------+--+
| 123,456,789.00 | 123,456,789 | 123,456,789.00000 |
+-----------------+--------------+--------------------+--+
8. json解析函數:get_json_object
語法: get_json_object(string json_string, string path)
返回值: string
描述: 解析json字符串json_string,返回path指定的內容。如果json_string無效,返回null
0: jdbc:hive2://node03:10000> 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');
+------+--+
| _c0 |
+------+--+
| amy |
+------+--+
9. 字符查找函數:instr
語法: instr(string str, string substr)
返回值: int
描述:返回substr在str中第一次出現的位置,查找不到返回0
0: jdbc:hive2://node03:10000> select instr('abcdef','c');
+------+--+
| _c0 |
+------+--+
| 3 |
+------+--+
10. 字符串長度函數: length
語法:length(string A)
返回值: int
描述: 返回字符串A的長度
0: jdbc:hive2://node03:10000> select length('hello');
+------+--+
| _c0 |
+------+--+
| 5 |
+------+--+
11. 字符串查找函數:locate
語法: locate(string substr, string str[, int pos])
返回值: int
描述:從pos位置開始查找,返回substr在str中第一次出現的位置。pos缺省爲1
0: jdbc:hive2://node03:10000> select locate('c', 'cabcdef') as col1, locate('c', 'cabcdef', 2) as col2;
+-------+-------+--+
| col1 | col2 |
+-------+-------+--+
| 1 | 4 |
+-------+-------+--+
12. 轉換小寫函數: lower / lcase
語法:lower(string A) / lcase(string A)
返回值: string
描述: 把字符串A轉換爲小寫
0: jdbc:hive2://node03:10000> select lower('fOoBaR') as lower, lcase('fOoBaR') as lcase;
+---------+---------+--+
| lower | lcase |
+---------+---------+--+
| foobar | foobar |
+---------+---------+--+
13. 轉換大寫函數:upper / ucase
語法:upper(string A) ucase(string A)
返回值: string
描述:把字符串A轉換爲大寫
0: jdbc:hive2://node03:10000> select upper('fOoBaR') as upper, ucase('fOoBaR') as ucase;
+---------+---------+--+
| upper | ucase |
+---------+---------+--+
| FOOBAR | FOOBAR |
+---------+---------+--+
14. 首字母大寫函數: initcap
語法:initcap(string A)
返回值:string
描述: A的首字母轉換爲大寫,其他轉換爲小寫
0: jdbc:hive2://node03:10000> select initcap('fOoBaR');
+---------+--+
| _c0 |
+---------+--+
| Foobar |
+---------+--+
15. 左補齊函數: lpad
語法: lpad(string str, int len, string pad)
返回值: string
描述: 使用pad左補齊str到len位。如果len小於str的長度,則str會被在尾部截斷。如果pad爲空,則返回值也爲空
0: jdbc:hive2://node03:10000> select lpad('abcdef', 8, '#') as col1,
. . . . . . . . . . . . . . > lpad('abcdef', 5, '#') as col2,
. . . . . . . . . . . . . . > lpad('abcdef', 8, '') as col3;
+-----------+--------+-------+--+
| col1 | col2 | col3 |
+-----------+--------+-------+--+
| ##abcdef | abcde | NULL |
+-----------+--------+-------+--+
16. 右補齊函數:rpad
語法:rpad(string str, int len, string pad)
返回值:string
描述: 使用pad右補齊str到len位。如果len小於str的長度,則str會被在尾部截斷。如果pad爲空,則返回值也爲空
0: jdbc:hive2://node03:10000> select rpad('abcdef', 8, '#') as col1,
. . . . . . . . . . . . . . > rpad('abcdef', 5, '#') as col2,
. . . . . . . . . . . . . . > rpad('abcdef', 8, '') as col3;
+-----------+--------+-------+--+
| col1 | col2 | col3 |
+-----------+--------+-------+--+
| abcdef## | abcde | NULL |
+-----------+--------+-------+--+
17. 去空格函數: trim
語法: trim(string A)
返回值: string
描述:去掉字符串A兩端的空格
0: jdbc:hive2://node03:10000> select concat('|',' foobar ','|') as notrim, concat('|',trim(' foobar '),'|') as trim;
+-------------+-----------+--+
| notrim | trim |
+-------------+-----------+--+
| | foobar | | |foobar| |
+-------------+-----------+--+
18. 左去空格函數:ltrim
語法:ltrim(string A)
返回值: string
描述:去掉字符串A左邊的空格
0: jdbc:hive2://node03:10000> select concat('|',' foobar ','|') as notrim, concat('|',ltrim(' foobar '),'|') as ltrim;
+-------------+------------+--+
| notrim | ltrim |
+-------------+------------+--+
| | foobar | | |foobar | |
+-------------+------------+--+
19. 右去空格函數: rtrim
語法: rtrim(string A)
返回值:string
描述: 去掉字符串A右邊的空格
0: jdbc:hive2://node03:10000> select concat('|',' foobar ','|') as notrim, concat('|',rtrim(' foobar '),'|') as rtrim;
+-------------+------------+--+
| notrim | rtrim |
+-------------+------------+--+
| | foobar | | | foobar| |
+-------------+------------+--+
20. URL解析函數: parse_url
語法:parse_url(string urlString, string partToExtract [, string keyToExtract])
返回值: string
描述: 返回URL中指定的部分。partToExtract的有效值爲:HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, USERINFO
0: jdbc:hive2://node03:10000> select parse_url('https://www.tableName.com/path1/p.php?k1=v1&k2=v2#Ref1','HOST') as host,
. . . . . . . . . . . . . . > parse_url('https://www.tableName.com/path1/p.php?k1=v1&k2=v2#Ref1','QUERY','k1') as k1,
. . . . . . . . . . . . . . > parse_url('https://www.tableName.com/path1/p.php?k1=v1&k2=v2#Ref1','PROTOCOL') as protocol;
+--------------------+-----+-----------+--+
| host | k1 | protocol |
+--------------------+-----+-----------+--+
| www.tableName.com | v1 | https |
+--------------------+-----+-----------+--+
21. 格式打印函數:printf
語法:printf(String format, Obj… args)
返回值:string
描述:返回按照printf中格式字符串format格式化後的輸入
0: jdbc:hive2://node03:10000> select printf('I am %d %s old', 28, 'years');
+--------------------+--+
| _c0 |
+--------------------+--+
| I am 28 years old |
+--------------------+--+
22. 正則解析函數:regexp_extract
語法: regexp_extract(string subject, string pattern, int index)
返回值: string
描述: 將字符串subject,按照pattern正則表達式拆分,返回index指定的部分
0: jdbc:hive2://node03:10000> select regexp_extract('foothebar', 'foo(.*?)(bar)', 1) as pattern1,
. . . . . . . . . . . . . . > regexp_extract('foothebar', 'foo(.*?)(bar)', 2) as pattern2,
. . . . . . . . . . . . . . > regexp_extract('foothebar', 'foo(.*?)(bar)', 0) as pattern0;
+-----------+-----------+------------+--+
| pattern1 | pattern2 | pattern0 |
+-----------+-----------+------------+--+
| the | bar | foothebar |
+-----------+-----------+------------+--+
23. 正則替換函數: regexp_replace
語法: regexp_replace(string INITIAL_STRING, string PATTERN, string REPLACEMENT)
返回值: string
描述: 將原字符串INITIAL_STRING中,符合PATTERN規則的替換爲REPLACEMENT
0: jdbc:hive2://node03:10000> select regexp_replace('hello world, hello hive','world|hive','NextAction');
+-------------------------------------+--+
| _c0 |
+-------------------------------------+--+
| hello NextAction, hello NextAction |
+-------------------------------------+--+
24. 重複函數: repeat
語法: repeat(string str, int n)
返回值: string
描述: 重複n次字符串str
0: jdbc:hive2://node03:10000> select repeat('I love China.',3);
+------------------------------------------+--+
| _c0 |
+------------------------------------------+--+
| I love China.I love China.I love China. |
+------------------------------------------+--+
25. 反轉函數:reverse
語法: reverse(string A)
返回值: string
描述: 反轉字符串A中的字符順序
0: jdbc:hive2://node03:10000> select reverse('NextAction');
+-------------+--+
| _c0 |
+-------------+--+
| noitcAtxeN |
+-------------+--+
26. 句子轉單詞函數:sentences
語法:sentences(string str, string lang, string locale)
返回值: array<array>
描述:將句子拆分爲包含單詞的數組,lang和locale是可選參數
0: jdbc:hive2://node03:10000> select sentences('Hello there! How are you?');
+------------------------------------------+--+
| _c0 |
+------------------------------------------+--+
| [["Hello","there"],["How","are","you"]] |
+------------------------------------------+--+
27. 空格生成函數:space
語法:space(int n)
返回值: string
描述:返回n個空格
0: jdbc:hive2://node03:10000> select concat('hello world', space(5), '!');
+--------------------+--+
| _c0 |
+--------------------+--+
| hello world ! |
+--------------------+--+
28. 字符串分割函數:split
語法: split(string str, string pat)
返回值: array
描述:按照pat分隔字符串str
0: jdbc:hive2://node03:10000> select split('abxefxmn', 'x');
+-------------------+--+
| _c0 |
+-------------------+--+
| ["ab","ef","mn"] |
+-------------------+--+
29. 字符串轉鍵值對函數:str_to_map
語法: str_to_map(text[, delimiter1, delimiter2])
返回值: map<string,string>
描述:將text分割爲K-V鍵值對。delimiter1將text分割爲多個K-V對,delimiter2再將K-V對分割。delimiter1缺省爲逗號(’,’),delimiter2缺省爲冒號(’:’)
0: jdbc:hive2://node03:10000> select str_to_map('name:NextAction,age:28,location:China', ',', ':');
+----------------------------------------------------+--+
| _c0 |
+----------------------------------------------------+--+
| {"location":"China","name":"NextAction","age":"28"} |
+----------------------------------------------------+--+
30. 字符串截取函數:substr / substring
語法: substr(string|binary A, int start, int len) / substring(string|binary A, int start, int len)
返回值: string
描述:將字符串A,從start位置開始,截取len位。如缺省len,默認截取到最後
0: jdbc:hive2://node03:10000> select substr('NextAction', 5) as sub_5,
. . . . . . . . . . . . . . > substr('NextAction', 5,1) as sub_5_1;
+---------+----------+--+
| sub_5 | sub_5_1 |
+---------+----------+--+
| Action | A |
+---------+----------+--+
31. 字符替換函數: translate
語法: translate(string|char|varchar input, string|char|varchar from, string|char|varchar to)
返回值: string
描述:將input中出現在from中的字符,按照to中對應位置的字符替換
0: jdbc:hive2://node03:10000> select translate('N1xtA23ion', '123', 'ect');
+-------------+--+
| _c0 |
+-------------+--+
| NextAction |
+-------------+--+