Hive列转行：
select school,concat_ws('|',collect_set(name)) as name from tmp_01 group by school;
注意：collect_set 有重复的会去重， collect_list 有重复的不去重
hive行转列：
select school,name,name_key
from tb_tmp_001
lateral view explode(split(name,',')) num as name_key where school=‘清华大学’;
注意：遇到特殊字符(“|”,””,”/”,”,”,”’”)无法分割时，需加 “\” 进行转译
Hive修改字段注释：
ALTER TABLE table_name CHANGE COLUMN muid muid_new STRING COMMENT '这里是列注释!';
例如：alter table tb_test change column id id string comment '用户号码';
Hive修改表注释：
ALTER TABLE table_name SET TBLPROPERTIES('comment' = '这是表注释!');
例如：ALTER TABLE tb_tmp_001 SET TBLPROPERTIES('comment' = '临时表!');
Hive数据导入：
create table tb_tmp_flink_sink_test(
id string,
sensor string,
)row format delimited
fields terminated by ' '
lines terminated by ' '
stored as textfile ;
方式一put:
Hdfs dfs -put /opt/datas/2nd_xa_05_price.csv /user/hive/warehouse/db_lianjia.db/tb_country/month_str=05/city_str=XA
ALTER TABLE tb_country ADD IF NOT EXISTS PARTITION (month_str="05",city_str="SH")
方式二load：
LOAD DATA LOCAL INPATH '/opt/datas/2nd_bj_05_price.csv' INTO TABLE tb_country PARTITION (month_str="05",city_str="BJ");
Hive数据导出：
方式一导入到本地：
insert overwrite local directory '/home/wyp/wyp' select * from wyp；
方式二导入到hdfs，再下载下来：
insert overwrite directory '/home/wyp/hdfs' select * from wyp;
hdfs get /home/wyp/hdfs /tmp/
hive创建数据库：
create database mydb1 location '/user/hive/mydb1';
hive建表语句：
2：使用MAP字段存储学生考试成绩
create table stu2(
id int,
name string,
scores map<string,int>
)row format delimited
fields terminated by ' '
collection items terminated by ','
map keys terminated by ':'
lines terminated by ' '
stored as textfile location '/user/admin/xiaojun/';hive建表语法中的分隔符设定
row format delimited 分隔符设置开始语句
fields terminated by：设置字段与字段之间的分隔符
collection items terminated by：设置一个复杂类型（array,struct)字段的各个item之间的分隔符
map keys terminated by：设置一个复杂类型(map)字段的key value之间的分隔符
lines terminated by：设置行与行之间的分隔符
Hive切换队列的三种方式：
set mapred.job.queue.name=queue3;
SET mapreduce.job.queuename=queue3;
set mapred.queue.names=queue3;
HIVE 设置任务名称
set mapred.job.name = my_job_name