1 INSERT OVERWRITE2 left semi3 col("create_time").cast("timestamp")4 data_trunc("hour","create_time")
1 INSERT OVERWRITE重刷覆盖数据
2 left semi提高效率 具体讲解
3 col(“create_time”).cast(“timestamp”)CAST (expression AS data_type) 具体讲解
4 data_trunc(“hour”,“create_time”)具体解决
举例
select date_trunc("minute","2018-03-14 10:32:00")
select date_trunc("hour","2018-03-14 10:32:00")
select date_trunc("day","2018-03-14 10:32:00")
select date_trunc("month","2018-03-14 10:32:00")
