Hive创建表及插入数据demo

create table student(id int comment "学生id",name string comment "学生姓名",age int comment "学生年龄")
comment "学生信息表"
row format delimited fields terminated by ",";

create external table student_ext(id int comment "学生id",name string comment "学生姓名",age int comment "学生年龄")
comment "学生信息表"
row format delimited fields terminated by ","
location "/user/hive/student_ext";

create external table student_ptn(id int comment "学生id",name string comment "学生姓名",age int comment "学生年龄")
comment "学生信息表"
partitioned by (city string)
row format delimited fields terminated by ","
location "/user/hive/student_ptn";

set hive.exec.dynamici.partition=true; #开启动态分区，默认是false
set hive.exec.dynamic.partition.mode=nonstrict; #开启允许所有分区都是动态的，否则必须要有静态分区才能使用。

set hive.exec.dynamic.partition=true;(可通过这个语句查看：set hive.exec.dynamic.partition;)
set hive.exec.dynamic.partition.mode=nonstrict;
SET hive.exec.max.dynamic.partitions=100000;(如果自动分区数大于这个参数，将会报错)
SET hive.exec.max.dynamic.partitions.pernode=100000;

insert into table student_ptn partition(city) select 6,"yangdong",29,"beijing";
insert into table student_ptn partition(city) select 2,"limei",22,"chongqing";
insert into table student_ptn partition(city) select 3,"wangxing",25,"beijing";
insert into table student_ptn partition(city) select 4,"chenming",22,"beijing";
insert into table student_ptn partition(city) select 5,"xiali",26,"chongqing";

create external table student_bck(id int comment "学生id",name string comment "学生姓名",age int comment "学生年龄")
comment "学生信息表"
clustered by(id) sorted by(id asc) into 2 buckets
row format delimited fields terminated by ","
location "/user/hive/student_bck";

insert into table student_bck
select * from student;

create table cdt(
id int,
name string,
work_location array,
piaofang map,
address struct)
row format delimited
fields terminated by "\t"
collection items terminated by ","
map keys terminated by ":"
lines terminated by "\n";

将json字符串加载到table json中
{"movie":"1193","rate":"5","timeStamp":"978300760","uid":"1"}
{"movie":"661","rate":"3","timeStamp":"978302109","uid":"1"}
{"movie":"914","rate":"3","timeStamp":"978301968","uid":"1"}
{"movie":"3408","rate":"4","timeStamp":"978300275","uid":"1"}
{"movie":"2355","rate":"5","timeStamp":"978824291","uid":"1"}
{"movie":"1197","rate":"3","timeStamp":"978302268","uid":"1"}
{"movie":"1287","rate":"5","timeStamp":"978302039","uid":"1"}
{"movie":"2804","rate":"5","timeStamp":"978300719","uid":"1"}
{"movie":"594","rate":"4","timeStamp":"978302268","uid":"1"}

CREATE TABLE json(
data string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe'
STORED AS INPUTFORMAT
'org.apache.hadoop.mapred.TextInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'
LOCATION
'hdfs://hmaster:9000/user/hive/warehouse/plusorg.db/json'
TBLPROPERTIES (
'transient_lastDdlTime'='1542008332')

load data local inpath "/root/json.txt" into table json;
get_json_object(data,'$.movie') 内置函数解析某列数据
select get_json_object(data,'$.movie') as movie from json;
json_tuple(jsonStr, k1, k2, ...) 内置函数解析json字符串类数据
参数为一组键k1，k2……和JSON字符串，返回值的元组。该方法比 get_json_object 高效，因为可以在一次调用中输入多个键

select
b.b_movie,
b.b_rate,
b.b_timeStamp,
b.b_uid
from json a
lateral view json_tuple(a.data,'movie','rate','timeStamp','uid') b as b_movie,b_rate,b_timeStamp,b_uid;

create table rate(movie int, rate int, unixtime int, userid int) row format delimited fields
terminated by '\t';

insert into table rate select
get_json_object(data,'$.movie') as moive,
get_json_object(data,'$.rate') as rate,
get_json_object(data,'$.timeStamp') as unixtime,
get_json_object(data,'$.uid') as userid
from json;

select from_unixtime(unixtime,'yyyy/MM/dd HH:mm:ss') from rate;

create table lastjsontable(movie int, rate int, utime date, userid int) row format delimited
fields terminated by '\t';
添加Python脚本，hive即可访问，路径为在当前Unix服务器存储绝对路径
add file /home/pythoncode/WeekdayMapper.py;

insert into table lastjsontable
select
transform(movie,rate,unixtime,userid) #输入值（基表）
using 'python WeekdayMapper.py' #使用脚本清洗
as(movie,rate,utime,userid) #输出值（子表）
from rate; #基表