一个数据项。
举例:
- data =
- {
- "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"
- }
get单层值
hive> select get_json_object(data, '$.owner') from test;
结果:amy
get多层值.
hive> select get_json_object(data, '$.store.bicycle.price') from test;
结果:19.95
get数组值[]
hive> select get_json_object(data, '$.store.fruit[0]') from test;
结果:{"weight":8,"type":"apple"}
如request ={“store”: {“fruit”:[{"weight":8,"type":"apple"},{"weight":9,"type":"pear"}], “bicycle”:{“price”:19.95,”color”:”red”} }
>get_json_object(request,'$.weight')
8
空格字符串函数:space
语法: space(int n)
返回值: string
说明:返回长度为n的字符串
举例:
hive> select space(10) from dual;
hive> select length(space(10)) from dual;
10
重复字符串函数:repeat
语法: repeat(string str, int n)
返回值: string
说明:返回重复n次后的str字符串
举例:
hive> select repeat(‘abc’,5) from dual;
abcabcabcabcabc
首字符ascii函数:ascii
语法: ascii(string str)
返回值: int
说明:返回字符串str第一个字符的ascii码
举例:
hive> select ascii(‘abcde’) from dual;
97
左补足函数:lpad
语法: lpad(string str, int len, string pad)
返回值: string
说明:将str进行用pad进行左补足到len位
举例:
hive> select lpad(‘abc’,10,’td’) from dual;
tdtdtdtabc
与GP,ORACLE不同,pad 不能默认
右补足函数:rpad
语法: rpad(string str, int len, string pad)
返回值: string
说明:将str进行用pad进行右补足到len位
举例:
hive> select rpad(‘abc’,10,’td’) from dual;
abctdtdtdt
分割字符串函数: split
语法: split(string str, string pat)
返回值: array
说明: 按照pat字符串分割str,会返回分割后的字符串数组
举例:
hive> select split(‘abtcdtef’,'t’) from dual;
["ab","cd","ef"]
集合查找函数: find_in_set
语法: find_in_set(string str, string strList)
返回值: int
说明: 返回str在strlist第一次出现的位置,strlist是用逗号分割的字符串。如果没有找该str字符,则返回0
举例:
hive> select find_in_set(‘ab’,'ef,ab,de’) from dual;
2
hive> select find_in_set(‘at’,'ef,ab,de’) from dual;
0