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📜  SQLite时间

📅  最后修改于: 2020-11-13 00:45:45             🧑  作者: Mango

SQLite时间函数

SQLite时间函数用于以“ HH-MM-SS”格式计算时间和返回时间。

句法：

time(timestring, [ modifier1, modifier2, ... modifier_n ] )

在这里，时间字符串是一个日期值，可以是以下任意一个：

Index timestring Description
1) now It is a literal used to return the current date.
2) YYYY-MM-DD It specifies the date value formatted as ‘YYYY-MM-DD’
3) YYYY-MM-DD HH:MM It specifies the date value formatted as ‘YYYY-MM-DD HH:MM’
4) YYYY-MM-DD HH:MM:SS It specifies the date value formatted as ‘YYYY-MM-DD HH:MM:SS’
5) YYYY-MM-DD HH:MM:SS.SSS It specifies the date value formatted as ‘YYYY-MM-DD HH:MM:SS.SSS’
6) HH:MM It specifies the date value formatted as ‘HH:MM’
7) HH:MM:SS It specifies the date value formatted as ‘HH:MM:SS’
8) HH:MM:SS.SSS It specifies the date value formatted as ‘HH:MM:SS.SSS’
9) YYYY-MM-DDTHH:MM It specifies the date value formatted as ‘YYYY-MM-DDTHH:MM’ where t is a literal character separating the date and time portions.
10) YYYY-MM-DDTHH:MM:SS It specifies the date value formatted as ‘YYYY-MM-DDTHH:MM:SS’ where t is a literal character separating the date and time portions
11) YYYY-MM-DDTHH:MM:SS.SSS It specifies the date value formatted as ‘YYYY-MM-DDTHH:MM:SS.SSS’ where t is a literal character separating the date and time portions
12) DDDDDDDDDD It specifies the Julian date number

修饰符1，修饰符2，…修饰符_n：修饰符是可选的。这些与时间字符串一起使用以增加或减少时间，日期或年份。

Index Modifier Description
1) [+-]NNN years It is used to specify number of years added/subtracted to the date
2) [+-]NNN months It is used to specify number of months added/subtracted to the date
3) [+-]NNN days It is used to specify number of days added/subtracted to the date
4) [+-]NNN hours It is used to specify number of hours added/subtracted to the date
5) [+-]NNN minutes It is used to specify number of minutes added/subtracted to the date
6) [+-]NNN seconds It is used to specify number of seconds added/subtracted to the date
7) [+-]NNN.NNNN seconds It is used to specify number of seconds (and fractional seconds) added/subtracted to the date
8) start of year It is used to shift the date back to the start of the year
9) start of month It is used to shift the date back to the start of the month
10) start of day It is used to shift the date back to the start of the day
11) weekday N It is used to move the date forward to the next date where weekday number is N
(0=Sunday, 1=Monday, 2=Tuesday, 3=Wednesday, 4=Thursday, 5=Friday, 6=Saturday)
12) unixepoch It is used with the DDDDDDDDDD timestring to interpret the date as UNIX Time (ie: number of seconds since 1970-01-01)
13) localtime It is used to adjust date to localtime, assuming the timestring was expressed in UTC
14) utc It is used to adjust date to utc, assuming the timestring was expressed in localtime

例1：检索当前时间：

SELECT time('now');

输出：

例2：在当前时间加上/减去小时和分钟：

SELECT time('11:23:02','-2 hours');
SELECT time('now','+5 hours');
SELECT time('11:15:02','+15 minutes');
SELECT time('now','-30 minutes');

输出：