Spark的一些函数或方法

Spark的一些函数或方法

文章目录

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")