获取当前时间并格式化
select from_unixtime(unix_timestamp(),'yyyy-MM-dd HH:mm:ss')
字符串解析为日期
select unix_timestamp('20111207 13:01:03','yyyyMMdd HH:mm:ss')
MapReduce计算模型
Hive 类型转换
cast(manual_dettime as bigint)
hive 导出数据时,加列名
hive -e “set hive.cli.print.header=true;select * from table” > data.csv
LATERAL VIEW
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+LateralView