日期時(shí)間型：
列類(lèi)型????????存儲(chǔ)需求
YEAR????????????1????????????1970~2069
TIME????????????3
DATE????????????3????????????1000-1-1~9999-12-31
DATETIME????????8????????????1000-1-1零點(diǎn)~9999-12-31二十三點(diǎn)59-59
TIMESTAMP?????? 4????????????1970-1-1零點(diǎn)~2037
2016-08-17
TIME????????????3 ? 要是定義時(shí)間00:00:00~23:59:59