Why is:
import spark.implicits._
val content = Seq(("2019", "09", "11","17","16","54","762000000")).toDF("year", "month", "day", "hour", "minute", "second", "nano")
content.printSchema
content.show
content.withColumn("event_time_utc", to_timestamp(concat('year, 'month, 'day, 'hour, 'minute, 'second), "yyyyMMddHHmmss"))
.withColumn("event_time_utc_millis", to_timestamp(concat('year, 'month, 'day, 'hour, 'minute, 'second, substring('nano, 0, 3)), "yyyyMMddHHmmssSSS"))
.select('year, 'month, 'day, 'hour, 'minute, 'second, 'nano,substring('nano, 0, 3), 'event_time_utc, 'event_time_utc_millis)
.show
缺少毫秒?
+----+-----+---+----+------+------+---------+---------------------+-------------------+---------------------+
|year|month|day|hour|minute|second| nano|substring(nano, 0, 3)| event_time_utc|event_time_utc_millis|
+----+-----+---+----+------+------+---------+---------------------+-------------------+---------------------+
|2019| 09| 11| 17| 16| 54|762000000| 762|2019-09-11 17:16:54| 2019-09-11 17:16:54|
+----+-----+---+----+------+------+---------+---------------------+-------------------+---------------------+
对于格式字符串:yyyyMMddHHmmssSSS
其中应包括毫秒SSS
如果我没有记错的话。