从Date型中，用Extract、to_char函数分别取年、月、日、时、分、秒的应用举例

 

       在Oracle做编程时，取年、月、日、时、分、秒就没有高级语言来的方便了。不过也有现成的函数支持。下面是一个小小的例子，供大家参考：

 

select extract(year from sysdate) "This Year ", extract(month from sysdate) "This Month ", extract(day from sysdate) "This Day ", --注意用Extract时，要用显示的timestamp类型 EXTRACT(HOUR FROM TIMESTAMP '2005-10-10 10:10:10') "This Hour", EXTRACT(MINUTE FROM TIMESTAMP '2005-10-10 10:10:10') "This Minute", EXTRACT(second FROM TIMESTAMP '2005-10-10 10:10:10') "This Second", to_char(sysdate, 'yyyy') "This Year", to_char(sysdate, 'mm') "This Month ", to_char(sysdate, 'dd') "This Day ", to_char(sysdate, 'hh24') "This Hour", to_char(sysdate, 'mi') "This Minute", to_char(sysdate, 'ss') "This Second" from dual;  

 

注意：用函数Extract取时、分、秒不像年、月、日那样直接可以从Date型里取，而是从TIMESTAMP标注，且后面加时间字符串形式。