从HADOOP平台导出文件

查看数据概况

show databases;

use dtname;

describe database dtname;

show tables;

describe tbname;

describe extended tbname;

表的分区字段

where语句中必须对某一分区字段进行限定;

show partitions tbname;

show partitions tbname partition(part1=para1);

查询数据

case when then 

like ... rlike ...

join

join on 

left/right/full outer join on 

sort by < order by 

cast

tablesample

union all

导出数据(1)

insert overwrite local directory "..." select ... from ... where ... limit ...;

导出数据(2)

queryengine -e "select ... from ..." > "absolute path"

常用的基本就这些.