3.1 基本資料型別

對於Hive的String型別相當於資料庫的varchar型別，該型別是一個可變的字串，不過它不能宣告其中最多能儲存多少個字元，理論上它可以儲存2GB的字元數。

做一個數據型別測試

create table person(id int , name string, weight double ,money bigint);

insert into table person values(1001,'yanban',60,100000000000);
 

3.2 集合資料型別

集合資料型別測試

songsong,bingbing_lili,xiao song:18_xiaoxiao song:19,hui long guan_beijing_10010
yangyang,caicai_susu,xiao yang:18_xiaoxiao yang:19,chao yang_beijing_10011

create table test(
name string,
friends array<string>,
children map<string,int>,
address struct<street:string,city:string,emaill:int>
)
row format delimited fields terminated by ','    --欄位分隔符
collection items terminated by '_'               --集合元素分隔符
map keys terminated by ':'                       --map的kv分隔符
lines terminated by '\n';                        --行分隔符
 

查 songsong 的第一個朋友 xiao song 年齡 ,郵編

select name,friends[0],children['xiao song'],address.email from test where name ='songsong';

select name,friends[0],children['xiao song'],address.email from test;

查 songsong 的第一個朋友,第一個孩子 ,郵編

select name,friends[0],map_keys(children)[0],address.email from test where name ='songsong';
select name,friends[0],map_values(children)[0],address.email from test where name ='songsong';

3.3 Hive 裡面的型別轉換

1. double在Hive裡面是最大 string可以轉成double
2. 強制型別轉化  cast('1' as type)