hive sql 语法总结

一、limit 语句

限制返回的行数

二、列别名

 count(1) as times 

三、嵌套select语句

 select xxx from (select xx from table1 ) a ;

四、case ...when ...then语句

用户处理单个列的查询结果

select name,
  case 
   when salay <50000 then 'low'
   when salay >=50000 and salary <70000 then 'middle'
   else 'high'
  end as bracket from employee;