hive将包含逗号的字段拆分为多列

目录

一、概述

二、行动

1.准备数据

2.数据清洗

3.substring_index函数

4.split函数实现

---

一、概述

想将hive表中包含逗号的字段按逗号做分隔符进行分列操作

二、行动

1.准备数据

--1
select '{1,2,3,4,5,6,7,8}' as num_str --使用的数据

2.数据清洗

--2
select 
      num_str
     ,replace(replace(num_str,'{',''),'}','')  as clean1 --清洗掉大括号
 from (
 select '{1,2,3,4,5,6,7,8}' as num_str --使用的数据
 ) t 

3.substring_index函数

函数介绍：

substring_index(string A, string delim, int count)

返回分隔符出现次数之前字符串A中的子字符串，count>0是从前往后截取，count<0是从后往前截取

--3
 select 
      num_str
     ,substring_index(replace(replace(num_str,'{',''),'}',''),',',1)  as index1   --从前往后1个分隔符
     ,substring_index(replace(replace(num_str,'{',''),'}',''),',',2)  as index2   --从前往后2个分隔符
     ,substring_index(replace(replace(num_str,'{',''),'}',''),',',3)  as index3   --从前往后3个分隔符
     ,substring_index(replace(replace(num_str,'{',''),'}',''),',',-1) as index_1  --从后往前1个分隔符
     ,substring_index(replace(replace(num_str,'{',''),'}',''),',',-2) as index_2  --从后往前2个分隔符
     ,substring_index(replace(replace(num_str,'{',''),'}',''),',',-3) as index_3  --从后往前3个分隔符
 from (
 select '{1,2,3,4,5,6,7,8}' as num_str --使用的数据
 ) t 

4.split函数实现

split(string str, string pat)

数组（注意下角标数字从0开始）

string str ：待分割字符串

string pat：分割符

--4
 select 
      num_str
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[0]          as s1
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[1]          as s2
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[2]          as s3
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[3]          as s4
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[4]          as s5
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[5]          as s6
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[6]          as s7
     ,split(replace(replace(num_str,'{',''),'}',''), ',')[7]          as s8
from (
 select '{1,2,3,4,5,6,7,8}' as num_str --使用的数据
 ) t 

由此可以看出，split函数可以实现我想要的效果，over~