得到當(dāng)前時(shí)間的年份、月份、天、小時(shí)等等：

YEAR (current timestamp)
MONTH (current timestamp)
DAY (current timestamp)
HOUR (current timestamp)
MINUTE (current timestamp)
SECOND (current timestamp)
MICROSECOND (current timestamp)

分別得到當(dāng)時(shí)的日期和時(shí)間

DATE (current timestamp)
TIME (current timestamp)

關(guān)于時(shí)間的一些計(jì)算：

current date + 1 YEAR
current date + 3 YEARS + 2 MONTHS + 15 DAYS
current time + 5 HOURS - 3 MINUTES + 10 SECONDS

計(jì)算兩個(gè)日期之間有多少天：

days (current date) - days (date(’1999-10-22′))

得到去除毫秒的當(dāng)前時(shí)間:

CURRENT TIMESTAMP - MICROSECOND (current timestamp) MICROSECONDS

將時(shí)間轉(zhuǎn)換成字符串：

char(current date)
char(current time)
char(current date + 12 hours)

將字符串轉(zhuǎn)換成時(shí)間：

TIMESTAMP (’2002-10-20-12.00.00.000000′)
TIMESTAMP (’2002-10-20 12:00:00′)
DATE (’2002-10-20′)
DATE (’10/20/2002′)
TIME (’12:00:00′)
TIME (’12.00.00′)