今天看啥
热点:

Hive中行列转换,Hive行列转换


1、演示多列转为单行
数据文件及内容: student.txt
xiaoming|english|92.0
xiaoming|chinese|98.0
xiaoming|math|89.5
huahua|chinese|80.0
huahua|math|89.5

创建表studnet:
create table student(name string,subject string,score decimal(4,1))
row format delimited
fields terminated by '|';

导入数据:
load data local inpath '/home/hadoop/hivetestdata/student.txt' into table student;


列转为行演示:
hive (hive)> select name,concat_ws(',',collect_set(subject)) from student group by name;
huahua    chinese,math
xiaoming english,chinese,math


hive (hive)> select name,concat_ws(',',collect_set(concat(subject,'=',score))) from student group by name;
huahua chinese=80,math=89.5
xiaoming english=92,chinese=98,math=89.5


2、演示单行转为多列
数据文件及内容:student2.txt
huahua|chinese=80,math=89.5
xiaoming|english=92,chinese=98,math=89.5

创建表:
create table student2(name string,subject_score_list string)
row format delimited

fields terminated by '|';

导入数据:

load data local inpath '/home/hadoop/hivetestdata/student2.txt' into table student2;

行转为列演示:
hive (hive)> select * from student2;
student2.name student2.subject_score_list
huahua             chinese=80,math=89.5
xiaoming          english=92,chinese=98,math=89.5


hive (hive)> select name, subject_list from student2 stu2 lateral view explode(split(stu2.subject_score_list,','))stu_subj as subject_list; ----别名一定不要忘记
huahua    chinese=80
huahua    math=89.5
xiaoming english=92
xiaoming chinese=98
xiaoming math=89.5


Impala的行列转换请查看: http://blog.csdn.net/jiangshouzhuang/article/details/46809931

版权声明:本文为博主原创文章,未经博主允许不得转载。

www.bkjia.comtruehttp://www.bkjia.com/sjkqy/1029121.htmlTechArticleHive中行列转换,Hive行列转换 1、演示多列转为单行 数据文件及内容: student.txt xiaoming|english|92.0 xiaoming|chinese|98.0 xiaoming|math|89.5 huahua|chine...

相关文章

    暂无相关文章
相关搜索:

帮客评论

视觉看点