Date time functions 默认数据格式为yyyy-MM-dd格式
DataFrame数据
val df = Seq(
("A", "2019-01-10", "2019-05-02"),
("B", "2019-01-01", "2019-02-04"),
("D", "2019-01-09", "2019-03-02"))
.toDF("user_id", "start_time", "end_time")
1. defadd_months(startDate: Column, numMonths: Int): Column
def add_months 在月份上增加/减少n个月,其中正式表示增加,负数表示减少。
df.select(add_months(col("start_time"), 1).as("add_months")).show() +----------+ |add_months| +----------+ |2019-02-10| |2019-02-01| |2019-02-09| +----------+
2. def current_date(): Column
获取当前时间的年月日
df.select(current_date()).show() +--------------+ |current_date()| +--------------+ | 2020-04-01| | 2020-04-01| | 2020-04-01| +--------------+
3. def current_timestamp(): Column
获取当前时间的时间戳
df.select(current_timestamp()).show() +--------------------------------------+ | current_timestamp() | +--------------------------------------+ |2020-04-01T09:40:03.051+08:00 | |2020-04-01T09:40:03.051+08:00 | |2020-04-01T09:40:03.051+08:00 | +--------------------------------------+
4. def date_add(start: Column, days: Int): Column
在天格式上增加天数
df.select(date_add(col("start_time"),1)).show() +-----------------------+ |date_add(start_time, 1)| +-----------------------+ | 2019-01-11| | 2019-01-02| | 2019-01-10| +-----------------------+
5. def date_format(dateExpr: Column, format: String): Column
将date/timestamp/string,转化为第二个参数的格式形式