Hive Learning Notes---Array, Map, struct type use

Hive provides a variety of composite data types:

Array, Struct, Map

struct use:

Hive> CREATE TABLE Student_test (ID INT, info struct<name:string, age:int>)
    > ROW FORMAT delimited FIELDS T erminated by ', '                       
    > COLLECTION ITEMS terminated by ': ';  

' FIELDS terminated by ': Separator between field and field
' COLLECTION ITEMS terminated by ': separator for each item in a field

Import data:

$ cat Test5.txt 
1,zhou:30
2,yan:30
3,chen:20
4,li:80 hive>
LOAD DATA local inpath '/home/work/ Data/test5.txt ' into TABLE student_test;
Copying data from File:/home/work/data/test5.txt
copying file:file:/home/work/data/test5.txt
Loading data To table Default.student_test
OK time
taken:0.35 seconds

Inquire:

Hive> select Info.age from Student_test;
Total MapReduce jobs = 1.
Total MapReduce CPU time spent:490 msec
OK
taken:21.677 seconds

Array uses
Build table:

Hive> CREATE table Class_test (name string, student_id_list array<int>)
    > ROW FORMAT delimited                                            
    > FIELDS terminated by ', '                                        
    > COLLECTION ITEMS terminated by ': ';                             
OK Time
taken:0.099 seconds

Import data:

$ cat Test6.txt 
034,1:2:3:4
035,5:6
036,7:8:9:10
hive>  LOAD DATA local inpath '/home/work/ Data/test6.txt ' into TABLE class_test;
Copying data from File:/home/work/data/test6.txt
copying file:file:/home/work/data/test6.txt
Loading data to Table Default.class_test
OK time
taken:0.198 seconds

Inquire:

Hive> Select student_id_list[3] from Class_test;
Total MapReduce jobs = 1.
Total MapReduce CPU time spent:480 msec
OK
4
NULL
time
taken:21.574 seconds

Map uses
Build table:

Hive> CREATE TABLE employee (ID string, perf map<string, int>)     
    > ROW FORMAT delimited                                        
    > FIELDS termi nated by ' \ t '                              
    > COLLECTION ITEMS terminated by ', '                     
    > MAP KEYS terminated by ': ';                                  
OK Time
taken:0.144 seconds

' MAP KEYS terminated by ': Key value Separator

Import data:

$ cat Test7.txt 
1       job:80,team:60,person:70
2       job:60,team:80
3       Job:90,team:70,person :
hive>  LOAD DATA local inpath '/home/work/data/test7.txt ' into TABLE employee;

Inquire:

hive> Select perf[' person ' from employee;
Total MapReduce jobs = 1.
Total MapReduce CPU time spent:460 msec
OK
NULL-time
taken:20.902 seconds
hive>   Select perf[' person ' to from employee where perf[' who ' is not null; Total
MapReduce jobs = 1.
Total MapReduce CPU time spent:610 msec
OK
time
taken:21.989 seconds hive>
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