Kevin的技術家園

MOD(10,3)? MOD(3,3)? MOD(2,3)

--------- --------- ---------

1???????? 0???????? 2

27.POWER 返回n1的n2次方根

SQL> select power(2,10),power(3,3) from dual;

POWER(2,10) POWER(3,3)

----------- ----------

1024???????? 27

28.ROUND和TRUNC

按照指定的精度進行舍入

SQL> select round(55.5),round(-55.4),trunc(55.5),trunc(-55.5) from dual;

ROUND(55.5) ROUND(-55.4) TRUNC(55.5) TRUNC(-55.5)

----------- ------------ ----------- ------------

56????????? -55????????? 55????????? -55

29.SIGN 取數字n的符號,大于0返回1,小于0返回-1,等于0返回0

SQL> select sign(123),sign(-100),sign(0) from dual;

SIGN(123) SIGN(-100)?? SIGN(0)

--------- ---------- ---------

1???????? -1???????? 0

30.SIN 返回一個數字的正弦值

SQL> select sin(1.57079) from dual;

SIN(1.57079)

------------

1

31.SIGH 返回雙曲正弦的值

SQL> select sin(20),sinh(20) from dual;

SIN(20)? SINH(20)

--------- ---------

.91294525 242582598

32.SQRT 返回數字n的根

SQL> select sqrt(64),sqrt(10) from dual;

SQRT(64)? SQRT(10)

--------- ---------

8 3.1622777

33.TAN 返回數字的正切值

SQL> select tan(20),tan(10) from dual;

TAN(20)?? TAN(10)

--------- ---------

2.2371609 .64836083

34.TANH

返回數字n的雙曲正切值

SQL> select tanh(20),tan(20) from dual;

TANH(20)?? TAN(20)

--------- ---------

1 2.2371609

35.TRUNC

按照指定的精度截取一個數

SQL> select trunc(124.1666,-2) trunc1,trunc(124.16666,2) from dual;

TRUNC1 TRUNC(124.16666,2)

--------- ------------------

100???????????? 124.16

36.ADD_MONTHS

增加或減去月份

SQL> select to_char(add_months(to_date('199912','yyyymm'),2),'yyyymm') from dual;

TO_CHA

------

200002

SQL> select to_char(add_months(to_date('199912','yyyymm'),-2),'yyyymm') from dual;

TO_CHA

------

199910

37.LAST_DAY

返回日期的最后一天

SQL> select to_char(sysdate,'yyyy.mm.dd'),to_char((sysdate)+1,'yyyy.mm.dd') from dual;

TO_CHAR(SY TO_CHAR((S

---------- ----------

2004.05.09 2004.05.10

SQL> select last_day(sysdate) from dual;

LAST_DAY(S

----------

31-5月 -04

38.MONTHS_BETWEEN(date2,date1)

給出date2-date1的月份

SQL> select months_between('19-12月-1999','19-3月-1999') mon_between from dual;

MON_BETWEEN

-----------

9

SQL>selectmonths_between(to_date('2000.05.20','yyyy.mm.dd'),to_date('2005.05.20','yyyy.dd')) mon_betw from dual;

MON_BETW

---------

-60

39.NEW_TIME(date,'this','that')

給出在this時區=other時區的日期和時間

SQL> select to_char(sysdate,'yyyy.mm.dd hh24:mi:ss') bj_time,to_char(new_time

2? (sysdate,'PDT','GMT'),'yyyy.mm.dd hh24:mi:ss') los_angles from dual;

BJ_TIME???????????? LOS_ANGLES

------------------- -------------------

2004.05.09 11:05:32 2004.05.09 18:05:32

40.NEXT_DAY(date,'day')

給出日期date和星期x之后計算下一個星期的日期

SQL> select next_day('18-5月-2001','星期五') next_day from dual;

NEXT_DAY

----------

25-5月 -01

41.SYSDATE 用來得到系統的當前日期

SQL> select to_char(sysdate,'dd-mm-yyyy day') from dual;

TO_CHAR(SYSDATE,'

-----------------

09-05-2004 星期日

trunc(date,fmt)按照給出的要求將日期截斷,如果fmt='mi'表示保留分,截斷秒

SQL> select to_char(trunc(sysdate,'hh'),'yyyy.mm.dd hh24:mi:ss') hh,

2? to_char(trunc(sysdate,'mi'),'yyyy.mm.dd hh24:mi:ss') hhmm from dual;

HH????????????????? HHMM

------------------- -------------------

2004.05.09 11:00:00 2004.05.09 11:17:00

42.CHARTOROWID 將字符數據類型轉換為ROWID類型

SQL> select rowid,rowidtochar(rowid),ename from scott.emp;

ROWID????????????? ROWIDTOCHAR(ROWID) ENAME

------------------ ------------------ ----------

AAAAfKAACAAAAEqAAA AAAAfKAACAAAAEqAAA SMITH

AAAAfKAACAAAAEqAAB AAAAfKAACAAAAEqAAB ALLEN

AAAAfKAACAAAAEqAAC AAAAfKAACAAAAEqAAC WARD

AAAAfKAACAAAAEqAAD AAAAfKAACAAAAEqAAD JONES