按部分构建日期

SQL Server 中的时间序列分析

Maham Faisal Khan

Senior Data Science Content Developer

由部分构建日期

DATEFROMPARTS(year, month, day)

TIMEFROMPARTS(hour, minute, second, fraction, precision)

DATETIMEFROMPARTS(year, month, day, hour, minute, second, ms)

DATETIME2FROMPARTS(year, month, day, hour, minute, second, fraction, precision)

SMALLDATETIMEFROMPARTS(year, month, day, hour, minute)

DATETIMEOFFSETFROMPARTS(year, month, day, hour, minute, second, fraction, hour_offset, minute_offset, precision)

日期与时间合并

SELECT
    DATETIMEFROMPARTS(1918, 11, 11, 05, 45, 17, 995) AS DT,
    DATETIME2FROMPARTS(1918, 11, 11, 05, 45, 17, 0, 0) AS DT20,
    DATETIME2FROMPARTS(1918, 11, 11, 05, 45, 17, 995, 3) AS DT23,
    DATETIME2FROMPARTS(1918, 11, 11, 05, 45, 17, 9951234, 7) AS DT27;

DT	DT20	DT23	DT27
1918-11-11 05:45:17.997	1918-11-11 05:45:17	1918-11-11 05:45:17.995	1918-11-11 05:45:17.9951234

处理时区偏移

SELECT
    DATETIMEOFFSETFROMPARTS(2009, 08, 14, 21, 
        00, 00, 0, 5, 30, 0) AS IST,
    DATETIMEOFFSETFROMPARTS(2009, 08, 14, 21,
        00, 00, 0, 5, 30, 0)
        AT TIME ZONE 'UTC' AS UTC;

IST	UTC
2009-08-14 21:00:00 +05:30	2009-08-14 15:30:00 +00:00

按部分操作的注意事项

DATEFROMPARTS(1999, 12, NULL)

DATEFROMPARTS(10000, 01, 01)

DATETIME2FROMPARTS(1918, 11, 11, 05, 45, 17, 995, 0)

NULL

无法构造数据类型 date，部分参数无效。

无法构造数据类型 datetime2，部分参数无效。

练习时间！

SQL Server 中的时间序列分析