hive的复合数据类型

hive中的复合数据类型

• Array

array中的数据为相同类型，例如，假如array A中元素['a','b','c']，则A[1]的值为'b'

数据结构如下：
zhangsan	beijing,shanghai,tianjin,hangzhou
wangwu	shanghai,chengdu,wuhan,haerbin

create table complex_array(name string,work_locations array<string>) row format delimited fields terminated by '\t' collection items terminated by ',';

load data local inpath '/home/work/data/test1.txt' into table complex_array;

• Map

可以通过["指定key名称"]访问

1,zhangsan,唱歌:非常喜欢-跳舞:喜欢-游泳:一般般
2,lisi,打游戏:非常喜欢-篮球:不喜欢

create table complex_map(id int,name string,hobby map<string,string>)
row format delimited
fields terminated by ','
collection items terminated by '-'
map keys terminated by ':';

load data local inpath '/root/hivedata/complex_map.txt' into table complex_map;

以普通字符串映射：
create table complex_map_s(id int,name string,hobby string)
row format delimited
fields terminated by ',';

• Struct

集合元素可以类型不一样

例如c的类型为STRUCT{a INT; b INT}，我们可以通过c.a来访问域a

1,zhou:30
2,yan:30
3,chen:20
4,li:80

create table complex_struct(id int, info struct<name:STRING, age:INT>)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
COLLECTION ITEMS TERMINATED BY ':';   

load data local inpath '/home/work/data/test3.txt' into table complex_struct;

select info.age from complex_struct;