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  • Oracle SQL 内置函数大全(转)

    SQL中的单记录函数

    1.ASCII 返回与指定的字符对应的十进制数;
    SQL> select ascii('A') A,ascii('a') a,ascii('0') zero,ascii(' ') space from dual;

    A         A      ZERO     SPACE
    --------- --------- --------- ---------
    65        97        48        32


    2.CHR 给出整数,返回对应的字符;
    SQL> select chr(54740) zhao,chr(65) chr65 from dual;

    ZH C
    -- -
    赵 A

    3.CONCAT 连接两个字符串;
    SQL> select concat('010-','88888888')||'转23' 高乾竞电话 from dual;

    高乾竞电话
    ----------------
    010-88888888转23

    4.INITCAP 返回字符串并将字符串的第一个字母变为大写;
    SQL> select initcap('smith') upp from dual;

    UPP
    -----
    Smith

    5.INSTR(C1,C2,I,J) 在一个字符串中搜索指定的字符,返回发现指定的字符的位置;
    C1    被搜索的字符串
    C2    希望搜索的字符串
    I     搜索的开始位置,默认为1
    J     出现的位置,默认为1
    SQL> select instr('oracle traning','ra',1,2) instring from dual;

    INSTRING
    ---------
    9

    6.LENGTH 返回字符串的长度;
    SQL> select name,length(name),addr,length(addr),sal,length(to_char(sal)) from .nchar_tst;

    NAME   LENGTH(NAME) ADDR             LENGTH(ADDR)       SAL LENGTH(TO_CHAR(SAL))
    ------ ------------ ---------------- ------------ --------- --------------------
    高乾竞            3 北京市海锭区                6   9999.99                    7

    7.LOWER 返回字符串,并将所有的字符小写
    SQL> select lower('AaBbCcDd')AaBbCcDd from dual;

    AABBCCDD
    --------
    aabbccdd

    8.UPPER 返回字符串,并将所有的字符大写
    SQL> select upper('AaBbCcDd') upper from dual;

    UPPER
    --------
    AABBCCDD

    9.RPAD和LPAD(粘贴字符)
    RPAD 在列的右边粘贴字符
    LPAD 在列的左边粘贴字符
    SQL> select lpad(rpad('gao',10,'*'),17,'*')from dual;

    LPAD(RPAD('GAO',1
    -----------------
    *******gao*******
    不够字符则用*来填满

    10.LTRIM和RTRIM
    LTRIM 删除左边出现的字符串
    RTRIM 删除右边出现的字符串
    SQL> select ltrim(rtrim('   gao qian jing   ',' '),' ') from dual;

    LTRIM(RTRIM('
    -------------
    gao qian jing

    11.SUBSTR(string,start,count)
    取子字符串,从start开始,取count个
    SQL> select substr('13088888888',3,8) from dual;

    SUBSTR('
    --------
    08888888

    12.REPLACE('string','s1','s2')
    string   希望被替换的字符或变量
    s1       被替换的字符串
    s2       要替换的字符串
    SQL> select replace('he love you','he','i') from dual;

    REPLACE('HELOVEYOU','HE','I')
    ------------------------------
    i love you

    13.SOUNDEX 返回一个与给定的字符串读音相同的字符串
    SQL> create table table1(xm varchar(8));
    SQL> insert into table1 values('weather');
    SQL> insert into table1 values('wether');
    SQL> insert into table1 values('gao');

    SQL> select xm from table1 where soundex(xm)=soundex('weather');

    XM
    --------
    weather
    wether

    14.TRIM('s' from 'string')
    LEADING   剪掉前面的字符
    TRAILING 剪掉后面的字符
    如果不指定,默认为空格符

    15.ABS 返回指定值的绝对值
    SQL> select abs(100),abs(-100) from dual;

    ABS(100) ABS(-100)
    --------- ---------
    100       100

    16.ACOS 给出反余弦的值
    SQL> select acos(-1) from dual;

    ACOS(-1)
    ---------
    3.1415927

    17.ASIN 给出反正弦的值
    SQL> select asin(0.5) from dual;

    ASIN(0.5)
    ---------
    .52359878

    18.ATAN 返回一个数字的反正切值
    SQL> select atan(1) from dual;

    ATAN(1)
    ---------
    .78539816

    19.CEIL 返回大于或等于给出数字的最小整数
    SQL> select ceil(3.1415927) from dual;

    CEIL(3.1415927)
    ---------------
    4

    20.COS 返回一个给定数字的余弦
    SQL> select cos(-3.1415927) from dual;

    COS(-3.1415927)
    ---------------
    -1

    21.COSH 返回一个数字反余弦值
    SQL> select cosh(20) from dual;

    COSH(20)
    ---------
    242582598

    22.EXP 返回一个数字e的n次方根
    SQL> select exp(2),exp(1) from dual;

    EXP(2)    EXP(1)
    --------- ---------
    7.3890561 2.7182818

    23.FLOOR 对给定的数字取整数
    SQL> select floor(2345.67) from dual;

    FLOOR(2345.67)
    --------------
    2345

    24.LN 返回一个数字的对数值
    SQL> select ln(1),ln(2),ln(2.7182818) from dual;

    LN(1)     LN(2) LN(2.7182818)
    --------- --------- -------------
    0 .69314718     .99999999

    25.LOG(n1,n2) 返回一个以n1为底n2的对数
    SQL> select log(2,1),log(2,4) from dual;

    LOG(2,1) LOG(2,4)
    --------- ---------

    26.MOD(n1,n2) 返回一个n1除以n2的余数
    SQL> select mod(10,3),mod(3,3),mod(2,3) from dual;

    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
    按照指定的精度进行舍入
    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 取数字n的符号,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 返回一个数字的正弦值
    SQL> select sin(1.57079) from dual;

    SIN(1.57079)
    ------------
    1

    31.SIGH 返回双曲正弦的值
    SQL> select sin(20),sinh(20) from dual;

    SIN(20) SINH(20)
    --------- ---------
    .91294525 242582598

    32.SQRT 返回数字n的根
    SQL> select sqrt(64),sqrt(10) from dual;

    SQRT(64) SQRT(10)
    --------- ---------
    8 3.1622777

    33.TAN 返回数字的正切值
    SQL> select tan(20),tan(10) from dual;

    TAN(20)   TAN(10)
    --------- ---------
    2.2371609 .64836083

    34.TANH
    返回数字n的双曲正切值
    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个数
    SQL> select trunc(124.1666,-2) trunc1,trunc(124.16666,2) from dual;

    TRUNC1 TRUNC(124.16666,2)
    --------- ------------------
    100             124.16

    36.ADD_MONTHS
    增加或减去月份
    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)
    给出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')
    给出在this时区=other时区的日期和时间
    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')
    给出日期date和星期x之后计算下一个星期的日期
    SQL> select next_day('18-5月-2001','星期五') next_day from dual;

    NEXT_DAY
    ----------
    25-5月 -01

    41.SYSDATE 用来得到系统的当前日期
    SQL> select to_char(sysdate,'dd-mm-yyyy day') from dual;

    TO_CHAR(SYSDATE,'
    -----------------
    09-05-2004 星期日
    trunc(date,fmt)按照给出的要求将日期截断,如果fmt='mi'表示保留分,截断秒
    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 将字符数据类型转换为ROWID类型
    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

    43.CONVERT(c,dset,sset)
    将源字符串 sset从一个语言字符集转换到另一个目的dset字符集
    SQL> select convert('strutz','we8hp','f7dec') "conversion" from dual;

    conver
    ------
    strutz

    44.HEXTORAW 将一个十六进制构成的字符串转换为二进制

    45.RAWTOHEXT 将一个二进制构成的字符串转换为十六进制

    46.ROWIDTOCHAR 将ROWID数据类型转换为字符类型

    47.TO_CHAR(date,'format')
    SQL> select to_char(sysdate,'yyyy/mm/dd hh24:mi:ss') from dual;

    TO_CHAR(SYSDATE,'YY
    -------------------
    2004/05/09 21:14:41

    48.TO_DATE(string,'format') 将字符串转化为ORACLE中的一个日期

    49.TO_MULTI_BYTE 将字符串中的单字节字符转化为多字节字符
    SQL> select to_multi_byte('高') from dual;

    TO
    --

    50.TO_NUMBER
    将给出的字符转换为数字
    SQL> select to_number('1999') year from dual;

    YEAR
    ---------
    1999

    51.BFILENAME(dir,file)指定一个外部二进制文件
    SQL>insert into file_tb1 values(bfilename('lob_dir1','image1.gif'));

    52.CONVERT('x','desc','source') 将x字段或变量的源source转换为desc
    SQL> select sid,serial#,username,decode(command,
    2 0,'none',
    3 2,'insert',
    4 3,
    5 'select',
    6 6,'update',
    7 7,'delete',
    8 8,'drop',
    9 'other') cmd from v$session where type!='background';

    SID   SERIAL# USERNAME                       CMD
    --------- --------- ------------------------------ ------
    1         1                                none
    2         1                                none
    3         1                                none
    4         1                                none
    5         1                                none
    6         1                                none
    7      1275                                none
    8      1275                                none
    9        20 GAO                            select
    10        40 GAO                            none

    53.DUMP(s,fmt,start,length)
    DUMP函数以fmt指定的内部数字格式返回一个VARCHAR2类型的值
    SQL> col global_name for a30
    SQL> col dump_string for a50
    SQL> set lin 200
    SQL> select global_name,dump(global_name,1017,8,5) dump_string from global_name;

    GLOBAL_NAME                    DUMP_STRING
    ------------------------------ --------------------------------------------------
    ORACLE.WORLD                   Typ=1 Len=12 CharacterSet=ZHS16GBK: W,O,R,L,D

    54.EMPTY_BLOB()和EMPTY_CLOB()
    这两个函数都是用来对大数据类型字段进行初始化操作的函数

    55.GREATEST
    返回一组表达式中的最大值,即比较字符的编码大小.
    SQL> select greatest('AA','AB','AC') from dual;

    GR
    --
    AC
    SQL> select greatest('啊','安','天') from dual;

    GR
    --

    56.LEAST
    返回一组表达式中的最小值
    SQL> select least('啊','安','天') from dual;

    LE
    --

    57.UID
    返回标识当前用户的唯一整数
    SQL> show user
    USER 为"GAO"
    SQL> select username,user_id from dba_users where user_id=uid;

    USERNAME                         USER_ID
    ------------------------------ ---------
    GAO                                   25

    58.USER
    返回当前用户的名字
    SQL> select user from dual;

    USER
    ------------------------------
    GAO

    59.USEREVN
    返回当前用户环境的信息,opt可以是:
    ENTRYID,SESSIONID,TERMINAL,ISDBA,LABLE,LANGUAGE,CLIENT_INFO,LANG,VSIZE
    ISDBA 查看当前用户是否是DBA如果是则返回true
    SQL> select userenv('isdba') from dual;

    USEREN
    ------
    FALSE
    SQL> select userenv('isdba') from dual;

    USEREN
    ------
    TRUE
    SESSION
    返回会话标志
    SQL> select userenv('sessionid') from dual;

    USERENV('SESSIONID')
    --------------------
    152
    ENTRYID
    返回会话人口标志
    SQL> select userenv('entryid') from dual;

    USERENV('ENTRYID')
    ------------------
    0
    INSTANCE
    返回当前INSTANCE的标志
    SQL> select userenv('instance') from dual;

    USERENV('INSTANCE')
    -------------------
    1
    LANGUAGE
    返回当前环境变量
    SQL> select userenv('language') from dual;

    USERENV('LANGUAGE')
    ----------------------------------------------------
    SIMPLIFIED CHINESE_CHINA.ZHS16GBK
    LANG
    返回当前环境的语言的缩写
    SQL> select userenv('lang') from dual;

    USERENV('LANG')
    ----------------------------------------------------
    ZHS
    TERMINAL
    返回用户的终端或机器的标志
    SQL> select userenv('terminal') from dual;

    USERENV('TERMINA
    ----------------
    GAO
    VSIZE(X)
    返回X的大小(字节)数
    SQL> select vsize(user),user from dual;

    VSIZE(USER) USER
    ----------- ------------------------------
    6 SYSTEM

    43.CONVERT(c,dset,sset)
    将源字符串 sset从一个语言字符集转换到另一个目的dset字符集
    SQL> select convert('strutz','we8hp','f7dec') "conversion" from dual;

    conver
    ------
    strutz

    44.HEXTORAW 将一个十六进制构成的字符串转换为二进制

    45.RAWTOHEXT 将一个二进制构成的字符串转换为十六进制

    46.ROWIDTOCHAR 将ROWID数据类型转换为字符类型

    47.TO_CHAR(date,'format')
    SQL> select to_char(sysdate,'yyyy/mm/dd hh24:mi:ss') from dual;

    TO_CHAR(SYSDATE,'YY
    -------------------
    2004/05/09 21:14:41

    48.TO_DATE(string,'format') 将字符串转化为ORACLE中的一个日期

    49.TO_MULTI_BYTE 将字符串中的单字节字符转化为多字节字符
    SQL> select to_multi_byte('高') from dual;

    TO
    --

    50.TO_NUMBER
    将给出的字符转换为数字
    SQL> select to_number('1999') year from dual;

    YEAR
    ---------
    1999

    51.BFILENAME(dir,file)指定一个外部二进制文件
    SQL>insert into file_tb1 values(bfilename('lob_dir1','image1.gif'));

    52.CONVERT('x','desc','source') 将x字段或变量的源source转换为desc
    SQL> select sid,serial#,username,decode(command,
    2 0,'none',
    3 2,'insert',
    4 3,
    5 'select',
    6 6,'update',
    7 7,'delete',
    8 8,'drop',
    9 'other') cmd from v$session where type!='background';

    SID   SERIAL# USERNAME                       CMD
    --------- --------- ------------------------------ ------
    1         1                                none
    2         1                                none
    3         1                                none
    4         1                                none
    5         1                                none
    6         1                                none
    7      1275                                none
    8      1275                                none
    9        20 GAO                            select
    10        40 GAO                            none

    53.DUMP(s,fmt,start,length)
    DUMP函数以fmt指定的内部数字格式返回一个VARCHAR2类型的值
    SQL> col global_name for a30
    SQL> col dump_string for a50
    SQL> set lin 200
    SQL> select global_name,dump(global_name,1017,8,5) dump_string from global_name;

    GLOBAL_NAME                    DUMP_STRING
    ------------------------------ --------------------------------------------------
    ORACLE.WORLD                   Typ=1 Len=12 CharacterSet=ZHS16GBK: W,O,R,L,D

    54.EMPTY_BLOB()和EMPTY_CLOB()
    这两个函数都是用来对大数据类型字段进行初始化操作的函数

    55.GREATEST
    返回一组表达式中的最大值,即比较字符的编码大小.
    SQL> select greatest('AA','AB','AC') from dual;

    GR
    --
    AC
    SQL> select greatest('啊','安','天') from dual;

    GR
    --

    56.LEAST
    返回一组表达式中的最小值
    SQL> select least('啊','安','天') from dual;

    LE
    --

    57.UID
    返回标识当前用户的唯一整数
    SQL> show user
    USER 为"GAO"
    SQL> select username,user_id from dba_users where user_id=uid;

    USERNAME                         USER_ID
    ------------------------------ ---------
    GAO                                   25

    58.USER
    返回当前用户的名字
    SQL> select user from dual;

    USER
    ------------------------------
    GAO

    59.USEREVN
    返回当前用户环境的信息,opt可以是:
    ENTRYID,SESSIONID,TERMINAL,ISDBA,LABLE,LANGUAGE,CLIENT_INFO,LANG,VSIZE
    ISDBA 查看当前用户是否是DBA如果是则返回true
    SQL> select userenv('isdba') from dual;

    USEREN
    ------
    FALSE
    SQL> select userenv('isdba') from dual;

    USEREN
    ------
    TRUE
    SESSION
    返回会话标志
    SQL> select userenv('sessionid') from dual;

    USERENV('SESSIONID')
    --------------------
    152
    ENTRYID
    返回会话人口标志
    SQL> select userenv('entryid') from dual;

    USERENV('ENTRYID')
    ------------------
    0
    INSTANCE
    返回当前INSTANCE的标志
    SQL> select userenv('instance') from dual;

    USERENV('INSTANCE')
    -------------------
    1
    LANGUAGE
    返回当前环境变量
    SQL> select userenv('language') from dual;

    USERENV('LANGUAGE')
    ----------------------------------------------------
    SIMPLIFIED CHINESE_CHINA.ZHS16GBK
    LANG
    返回当前环境的语言的缩写
    SQL> select userenv('lang') from dual;

    USERENV('LANG')
    ----------------------------------------------------
    ZHS
    TERMINAL
    返回用户的终端或机器的标志
    SQL> select userenv('terminal') from dual;

    USERENV('TERMINA
    ----------------
    GAO
    VSIZE(X)
    返回X的大小(字节)数
    SQL> select vsize(user),user from dual;

    VSIZE(USER) USER
    ----------- ------------------------------
    6 SYSTEM

    本文转载自:https://www.cnblogs.com/lfx0692/articles/2395950.html

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  • 原文地址:https://www.cnblogs.com/test-7/p/10097721.html
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