Teradata中的日期/时间计算

Question

请帮助我在Teradata中计算一天的开始，一天的结束，月份的开始，月份的结束（以及最多3个时间）。 我想要这样的东西'2014-03-01 00：00：00.000'; 谢谢

Answer 1

这应该使您开始：

SELECT DATE
     , CAST(DATE AS INTEGER) AS DateInteger
     , CAST(((DATE / 100) * 100) + 1 AS DATE) AS MonthBegin
     , CAST((((DATE / 100) +1 ) * 100) + 1 AS DATE) AS NextMonthBegin
     , CAST((((DATE / 100) +1 ) * 100) + 1 AS DATE)  - 1 AS MonthEnd
     , CURRENT_TIMESTAMP(3)
     , CAST(CAST(CURRENT_TIMESTAMP(3) AS DATE) AS TIMESTAMP(3)) AS DayBegin
     , CAST((CAST(CURRENT_TIMESTAMP(3) AS DATE) + 1) AS TIMESTAMP(3)) - INTERVAL '0.001' SECOND AS DayEnd

*编辑*

SELECT CURRENT_DATE
     , CURRENT_DATE - EXTRACT( DAY FROM CURRENT_DATE) + 1 as MonthBegin
     , ADD_MONTHS(( CURRENT_DATE - EXTRACT (DAY FROM CURRENT_DATE) + 1), 1) as NextMonthBegin
     , ADD_MONTHS(( CURRENT_DATE - EXTRACT (DAY FROM CURRENT_DATE) + 1), 1) - 1 as MonthEnd
     , CURRENT_TIMESTAMP(3)
     , CAST( CAST(CURRENT_TIMESTAMP (3) AS DATE) AS TIMESTAMP (3)) AS DayBegin
     , CAST(( CAST(CURRENT_TIMESTAMP (3) AS DATE) + 1) AS TIMESTAMP (3)) - INTERVAL '0.001' SECOND AS DayEnd;

从这里应该可以将时间戳记为“月开始”，“月结束”和“下个月开始”。 让我知道您是否被卡住。