October 2002
Intermediate to advanced
1024 pages
27h 26m
English
You want to obtain just a part of a date or a time.
Use a formatting function such as
DATE_FORMAT( ) or TIME_FORMAT( )
with a format string that includes a specifier for the part of the
value you want to obtain.
MySQL provides several options for decomposing dates or times to
obtain their component values. The DATE_FORMAT( )
and TIME_FORMAT( ) functions provide one way to
extract individual parts of temporal values:
mysql>SELECT dt,->DATE_FORMAT(dt,'%Y') AS year,->DATE_FORMAT(dt,'%d') AS day,->TIME_FORMAT(dt,'%H') AS hour,->TIME_FORMAT(dt,'%s') AS second->FROM datetime_val;+---------------------+------+------+------+--------+ | dt | year | day | hour | second | +---------------------+------+------+------+--------+ | 1970-01-01 00:00:00 | 1970 | 01 | 00 | 00 | | 1987-03-05 12:30:15 | 1987 | 05 | 12 | 15 | | 1999-12-31 09:00:00 | 1999 | 31 | 09 | 00 | | 2000-06-04 15:45:30 | 2000 | 04 | 15 | 30 | +---------------------+------+------+------+--------+
Formatting functions allow you to extract more than one part of a
value. For example, to extract the entire date or time from
DATETIME values, do this:
mysql>SELECT dt,->DATE_FORMAT(dt,'%Y-%m-%d') AS 'date part',->TIME_FORMAT(dt,'%T') AS 'time part'->FROM datetime_val;+---------------------+------------+-----------+ | dt | date part | time part | +---------------------+------------+-----------+ | 1970-01-01 00:00:00 | 1970-01-01 | 00:00:00 ...