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( )A A ZERO SPACE--------- --------- --------- ---------65 97 48 322. CHR给出整数,返回对应的字符;SQL& select chr(54740) zhao,chr(65) chr65ZH C-- -赵 A3. CONCAT连接两个字符串;SQL& select concat(010-,)||转23 高乾竞电话高乾竞电话----------------010-4. 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-----Smith5.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1J 出现的位置,默认为1SQL& select instr(oracle traning,ra,1,2)INSTRING---------96.LENGTH返回字符串的长度;SQL& select name,length(name),addr,length(addr),sal,length(to_char(sal)) from gao.nchar_NAME LENGTH(NAME) ADDR LENGTH(ADDR) SAL LENGTH(TO_CHAR(SAL))------ ------------ ---------------- ------------ --------- --------------------高乾竞 3 北京市海锭区 6 7.LOWER返回字符串,并将所有的字符小写SQL& select lower(AaBbCcDd)AaBbCcDAABBCCDD--------aabbccdd8.UPPER返回字符串,并将所有的字符大写SQL& select upper(AaBbCcDd)UPPER--------AABBCCDD9.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,*)LPAD(RPAD(GAO,1-----------------*******gao*******不够字符则用*来填满10.LTRIM和RTRIMLTRIM 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 , ), )LTRIM(RTRIM(-------------gao qian jing11.SUBSTR(string,start,count)取子字符串,从start开始,取count个SQL& select substr(,3,8)SUBSTR(--------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)REPLACE(H----------i love you13.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--------weatherwether• 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)ABS(100) ABS(-100)--------- ---------100 10016.ACOS给出反余弦的值SQL& select acos(-1)ACOS(-1)---------3.141592717.ASIN给出反正弦的值SQL& select asin(0.5)ASIN(0.5)---------.18.ATAN返回一个数字的反正切值SQL& select atan(1)ATAN(1)---------.19.CEIL返回大于或等于给出数字的最小整数SQL& select ceil(3.1415927)CEIL(3.1415927)---------------420.COS返回一个给定数字的余弦SQL& select cos(-3.1415927)COS(-3.1415927)----------------121.COSH返回一个数字反余弦值SQL& select cosh(20)COSH(20)---------22.EXP返回一个数字e的n次方根SQL& select exp(2),exp(1)EXP(2) EXP(1)--------- ---------7..718281823.FLOOR对给定的数字取整数SQL& select floor(2345.67)FLOOR(2345.67)--------------234524.LN返回一个数字的对数值SQL& select ln(1),ln(2),ln(2.7182818)LN(1) LN(2) LN(2.7182818)--------- --------- -------------0 .99999925.LOG(n1,n2)返回一个以n1为底n2的对数& SQL& select log(2,1),log(2,4)LOG(2,1) LOG(2,4)--------- ---------0 226.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)MOD(10,3) MOD(3,3) MOD(2,3)--------- --------- ---------1 0 227.POWER返回n1的n2次方根SQL& select power(2,10),power(3,3)POWER(2,10) POWER(3,3)----------- ----------1024 2728.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)ROUND(55.5) ROUND(-55.4) TRUNC(55.5) TRUNC(-55.5)----------- ------------ ----------- ------------56 -55 55 -5529.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0SQL& select sign(123),sign(-100),sign(0)SIGN(123) SIGN(-100) SIGN(0)--------- ---------- ---------1 -1 030.SIN返回一个数字的正弦值SQL& select sin(1.57079)SIN(1.57079)------------1• 31.SIGH返回双曲正弦的值SQL& select sin(20),sinh(20)SIN(20) SINH(20)--------- ---------.58259832.SQRT返回数字n的根SQL& select sqrt(64),sqrt(10)SQRT(64) SQRT(10)--------- ---------8 3.162277733.TAN返回数字的正切值SQL& select tan(20),tan(10)TAN(20) TAN(10)--------- ---------2.83608334.TANH返回数字n的双曲正切值SQL& select tanh(20),tan(20)TANH(20) TAN(20)--------- ---------1 2.237160935.TRUNC按照指定的精度截取一个数SQL& select trunc(124.1666,-2) trunc1,trunc(124.16666,2)TRUNC1 TRUNC(124.16666,2)--------- ------------------100 124.1636.ADD_MONTHS增加或减去月份SQL& select to_char(add_months(to_date(199912,yyyymm),2),yyyymm)TO_CHA------200002SQL& select to_char(add_months(to_date(199912,yyyymm),-2),yyyymm)TO_CHA------19991037.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)TO_CHAR(SY TO_CHAR((S---------- ---------- SQL& select last_day(sysdate)LAST_DAY(S----------31-5月 -0438.MONTHS_BETWEEN(date2,date1)给出date2-date1的月份SQL& select months_between(19-12月-月-1999) mon_MON_BETWEEN-----------9SQL&selectmonths_between(to_date(,yyyy.mm.dd),to_date(,yyyy.mm.dd)) mon_MON_BETW----------6039.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_time2 (sysdate,PDT,GMT),yyyy.mm.dd hh24:mi:ss) los_BJ_TIME LOS_ANGLES------------------- ------------------- 11:05:32
18:05:3240.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_NEXT_DAY----------25-5月 -0141.SYSDATE用来得到系统的当前日期SQL& select to_char(sysdate,dd-mm-yyyy day)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)HH HHMM------------------- ------------------- 11:00:00
11:17:0042.CHARTOROWID将字符数据类型转换为ROWID类型SQL& select rowid,rowidtochar(rowid),ename from scott.ROWID ROWIDTOCHAR(ROWID) ENAME------------------ ------------------ ----------AAAAfKAACAAAAEqAAA AAAAfKAACAAAAEqAAA SMITHAAAAfKAACAAAAEqAAB AAAAfKAACAAAAEqAAB ALLENAAAAfKAACAAAAEqAAC AAAAfKAACAAAAEqAAC WARDAAAAfKAACAAAAEqAAD AAAAfKAACAAAAEqAAD JONES43.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"conver------strutz44.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)TO_CHAR(SYSDATE,YY------------------- 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)TO--高50.TO_NUMBER将给出的字符转换为数字SQL& select to_number(1999)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descSQL& 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!=SID SERIAL# USERNAME CMD--------- --------- ------------------------------ ------1 1 none2 1 none3 1 none4 1 none5 1 none6 1 none7 1275 none8 1275 none9 20 GAO select10 40 GAO none53.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 a30SQL& col dump_string for a50SQL& set lin 200SQL& select global_name,dump(global_name,) dump_string from global_GLOBAL_NAME DUMP_STRING------------------------------ --------------------------------------------------ORACLE.WORLD Typ=1 Len=12 CharacterSet=ZHS16GBK: W,O,R,L,D54.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)GR--ACSQL& select greatest(啊,安,天)GR--天56.LEAST返回一组表达式中的最小值& SQL& select least(啊,安,天)LE--啊57.UID返回标识当前用户的唯一整数SQL& show userUSER 为"GAO"SQL& select username,user_id from dba_users where user_id=USERNAME USER_ID------------------------------ ---------GAO 2558.USER返回当前用户的名字SQL& sUSER------------------------------GAO59.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,VSIZEISDBA 查看当前用户是否是DBA如果是则返回trueSQL& select userenv(isdba)USEREN------FALSESQL& select userenv(isdba)USEREN------TRUESESSION返回会话标志SQL& select userenv(sessionid)USERENV(SESSIONID)--------------------152ENTRYID返回会话人口标志SQL& select userenv(entryid)USERENV(ENTRYID)------------------0INSTANCE返回当前INSTANCE的标志SQL& select userenv(instance)USERENV(INSTANCE)-------------------1LANGUAGE返回当前环境变量SQL& select userenv(language)USERENV(LANGUAGE)----------------------------------------------------SIMPLIFIED CHINESE_CHINA.ZHS16GBKLANG返回当前环境的语言的缩写SQL& select userenv(lang)USERENV(LANG)----------------------------------------------------ZHSTERMINAL返回用户的终端或机器的标志SQL& select userenv(terminal)USERENV(TERMINA----------------GAOVSIZE(X)返回X的大小(字节)数SQL& select vsize(user),VSIZE(USER) USER----------- ------------------------------6 SYSTEM• 60.AVG(DISTINCT|ALL)all表示对所有的值求平均值,distinct只对不同的值求平均值SQLWKS& create table table3(xm varchar(8),sal number(7,2));语句已处理。SQLWKS& insert into table3 values(gao,1111.11);SQLWKS& insert into table3 values(gao,1111.11);SQLWKS& insert into table3 values(zhu,5555.55);SQLWKS&SQL& select avg(distinct sal) from gao.table3;AVG(DISTINCTSAL)----------------3333.33SQL& select avg(all sal) from gao.table3;AVG(ALLSAL)-----------2592.5961.MAX(DISTINCT|ALL)求最大值,ALL表示对所有的值求最大值,DISTINCT表示对不同的值求最大值,相同的只取一次SQL& select max(distinct sal) from scott.MAX(DISTINCTSAL)----------------500062.MIN(DISTINCT|ALL)求最小值,ALL表示对所有的值求最小值,DISTINCT表示对不同的值求最小值,相同的只取一次SQL& select min(all sal) from gao.table3;MIN(ALLSAL)-----------1111.1163.STDDEV(distinct|all)求标准差,ALL表示对所有的值求标准差,DISTINCT表示只对不同的值求标准差SQL& select stddev(sal) from scott.STDDEV(SAL)-----------SQL& select stddev(distinct sal) from scott.STDDEV(DISTINCTSAL)-------------------64.VARIANCE(DISTINCT|ALL)求协方差& SQL& select variance(sal) from scott.VARIANCE(SAL)-------------65.GROUP BY主要用来对一组数进行统计SQL& select deptno,count(*),sum(sal) from scott.DEPTNO COUNT(*) SUM(SAL)--------- --------- ---------10 3 875020 5 1087530 6 940066.HAVING对分组统计再加限制条件SQL& select deptno,count(*),sum(sal) from scott.emp group by deptno having count(*)&=5;DEPTNO COUNT(*) SUM(SAL)--------- --------- ---------20 5 1087530 6 9400SQL& select deptno,count(*),sum(sal) from scott.emp having count(*)&=5DEPTNO COUNT(*) SUM(SAL)--------- --------- ---------20 5 1087530 6 940067.ORDER BY用于对查询到的结果进行排序输出SQL& select deptno,ename,sal from scott.emp order by deptno,DEPTNO ENAME SAL--------- ---------- ---------10 KING 500010 CLARK 245010 MILLER 130020 SCOTT 300020 FORD 300020 JONES 297520 ADAMS 110020 SMITH 80030 BLAKE 285030 ALLEN 160030 TURNER 150030 WARD 125030 MARTIN 125030 JAMES 950& 68. pl/sql中的case语句select (case when DUMMY='X' then 0 else 1 end)& case的第1种用法：case col when 'a' then 1when 'b' then 2else 0 end这种用法跟decode一样没什么区别case的第2种用法：case when score &60 then 'd'when score &=60 and score &70 then 'c'when score &=70 and score &80 then 'b'else 'a' end69.NVL(expr1, expr2)NVL(expr1, expr2)-&expr1为NULL，返回expr2；不为NULL，返回expr1。注意两者的类型要一致& NVL2 (expr1, expr2, expr3) -&expr1不为NULL，返回expr2；为NULL，返回expr3。expr2和expr3类型不同的话，expr3会转换为expr2的类型& NULLIF (expr1, expr2) -&相等返回NULL，不等返回expr1• Oracle分析函数参考手册& =============================================作者: xsb(发表于: 12:22分类: DW&BI& 出处：http://xsb.itpub.net/post/419/33028---------------------------------------------------------------& & Oracle从8.1.6开始提供分析函数，分析函数用于计算基于组的某种聚合值，它和聚合函数的不同之处是对于每个组返回多行，而聚合函数对于每个组只返回一行。常用的分析函数如下所列:row_number() over(partition by ... order by ...)rank() over(partition by ... order by ...)dense_rank() over(partition by ... order by ...)count() over(partition by ... order by ...)max() over(partition by ... order by ...)min() over(partition by ... order by ...)sum() over(partition by ... order by ...)avg() over(partition by ... order by ...)first_value() over(partition by ... order by ...)last_value() over(partition by ... order by ...)lag() over(partition by ... order by ...)lead() over(partition by ... order by ...)& 下面例子中使用的表来自Oracle自带的HR用户下的表，如果没有安装该用户，可以在SYS用户下运行$ORACLE_HOME/demo/schema/human_resources/hr_main.sql来创建。除本文内容外，你还可参考：ROLLUP与CUBE 分析函数使用例子介绍：本文如果未指明，缺省是在HR用户下运行例子。开窗函数的的理解：开窗函数指定了分析函数工作的数据窗口大小，这个数据窗口大小可能会随着行的变化而变化，举例如下：over（order by salary） 按照salary排序进行累计，order by是个默认的开窗函数over（partition by deptno）按照部门分区over（order by salary range between 50 preceding and 150 following）每行对应的数据窗口是之前行幅度值不超过50，之后行幅度值不超过150over（order by salary rows between 50 preceding and 150 following）每行对应的数据窗口是之前50行，之后150行over（order by salary rows between unbounded preceding and unbounded following）每行对应的数据窗口是从第一行到最后一行，等效：over（order by salary range between unbounded preceding and unbounded following）主要参考资料：《expert one-on-one》 Tom Kyte 《Oracle9i SQL Reference》第6章& ohwww
09:19& &续70。AVG& 功能描述：用于计算一个组和数据窗口内表达式的平均值。SAMPLE：下面的例子中列c_mavg计算员工表中每个员工的平均薪水报告，该平均值由当前员工和与之具有相同经理的前一个和后一个三者的平均数得来；SELECT manager_id, last_name, hire_date, salary,AVG(salary) OVER (PARTITION BY manager_id ORDER BY hire_date& ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS c_mavgFROMMANAGER_ID LAST_NAME HIRE_DATE SALARY C_MAVG---------- ------------------------- --------- ---------- ----------100 Kochhar 21-SEP-89 100 De Haan 13-JAN-93 100 Raphaely 07-DEC-94 .6667100 Kaufling 01-MAY-95 .3333100 Hartstein 17-FEB-96 .33333100 Weiss 18-JUL-96 .6667100 Russell 01-OCT-96 .333371。CORR& 功能描述：返回一对表达式的相关系数，它是如下的缩写：COVAR_POP(expr1,expr2)/STDDEV_POP(expr1)*STDDEV_POP(expr2))从统计上讲，相关性是变量之间关联的强度，变量之间的关联意味着在某种程度上一个变量的值可由其它的值进行预测。通过返回一个-1~1之间的一个数, 相关系数给出了关联的强度，0表示不相关。SAMPLE：下例返回1998年月销售收入和月单位销售的关系的累积系数（本例在SH用户下运行）SELECT t.calendar_month_number,CORR (SUM(s.amount_sold), SUM(s.quantity_sold))OVER (ORDER BY t.calendar_month_number) as CUM_CORRFROM sales s, times tWHERE s.time_id = t.time_id AND calendar_year = 1998GROUP BY t.calendar_month_numberORDER BY t.calendar_month_CALENDAR_MONTH_NUMBER CUM_CORR--------------------- ----------12 13 .4 .5 .6 .7 .8 .9 .10 .11 .12 .72。COVAR_POP& 功能描述：返回一对表达式的总体协方差。SAMPLE：下例CUM_COVP返回定价和最小产品价格的累积总体协方差SELECT product_id, supplier_id,COVAR_POP(list_price, min_price)& OVER (ORDER BY product_id, supplier_id) AS CUM_COVP,COVAR_SAMP(list_price, min_price)OVER (ORDER BY product_id, supplier_id) AS CUM_COVS& FROM product_information pWHERE category_id = 29ORDER BY product_id, supplier_PRODUCT_ID SUPPLIER_ID CUM_COVP CUM_COVS---------- ----------- ---------- ---------- 0 6.5
8.33333 9.25 5
..73。COVAR_SAMP& 功能描述：返回一对表达式的样本协方差SAMPLE：下例CUM_COVS返回定价和最小产品价格的累积样本协方差SELECT product_id, supplier_id,COVAR_POP(list_price, min_price)& OVER (ORDER BY product_id, supplier_id) AS CUM_COVP,COVAR_SAMP(list_price, min_price)OVER (ORDER BY product_id, supplier_id) AS CUM_COVS& FROM product_information pWHERE category_id = 29ORDER BY product_id, supplier_PRODUCT_ID SUPPLIER_ID CUM_COVP CUM_COVS---------- ----------- ---------- ---------- 0 6.5
8.33333 9.25 5
• 74。COUNT& 功能描述：对一组内发生的事情进行累积计数，如果指定*或一些非空常数，count将对所有行计数，如果指定一个表达式，count返回表达式非空赋值的计数，当有相同值出现时，这些相等的值都会被纳入被计算的值；可以使用DISTINCT来记录去掉一组中完全相同的数据后出现的行数。SAMPLE：下面例子中计算每个员工在按薪水排序中当前行附近薪水在[n-50,n+150]之间的行数，n表示当前行的薪水例如，Philtanker的薪水2200，排在他之前的行中薪水大于等于2200-50的有1行，排在他之后的行中薪水小于等于的行没有，所以count计数值cnt3为2（包括自己当前行）；cnt2值相当于小于等于当前行的SALARY值的所有行数SELECT last_name, salary, COUNT(*) OVER () AS cnt1,COUNT(*) OVER (ORDER BY salary) AS cnt2,COUNT(*) OVER (ORDER BY salary RANGE BETWEEN 50 PRECEDINGAND 150 FOLLOWING) AS cnt3 FROMLAST_NAME SALARY CNT1 CNT2 CNT3------------------------- ---------- ---------- ---------- ----------Olson
2Philtanker
8Colmenares
10..75。CUME_DIST& 功能描述：计算一行在组中的相对位置，CUME_DIST总是返回大于0、小于或等于1的数，该数表示该行在N行中的位置。例如，在一个3行的组中，返回的累计分布值为1/3、2/3、3/3SAMPLE：下例中计算每个工种的员工按薪水排序依次累积出现的分布百分比SELECT job_id, last_name, salary, CUME_DIST()& OVER (PARTITION BY job_id ORDER BY salary) AS cume_distFROM employees WHERE job_id LIKE 'PU%';JOB_ID LAST_NAME SALARY CUME_DIST---------- ------------------------- ---------- ----------PU_CLERK Colmenares 2500 .2PU_CLERK Himuro 2600 .4PU_CLERK Tobias 2800 .6PU_CLERK Baida 2900 .8PU_CLERK Khoo 3100 1PU_MAN Raphaely 11000 176。DENSE_RANK& 功能描述：根据ORDER BY子句中表达式的值，从查询返回的每一行，计算它们与其它行的相对位置。组内的数据按ORDER BY子句排序，然后给每一行赋一个号，从而形成一个序列，该序列从1开始，往后累加。每次ORDER BY表达式的值发生变化时，该序列也随之增加。有同样值的行得到同样的数字序号（认为null时相等的）。密集的序列返回的时没有间隔的数SAMPLE：下例中计算每个员工按部门分区再按薪水排序，依次出现的序列号（注意与RANK函数的区别）SELECT d.department_id , e.last_name, e.salary, DENSE_RANK()& OVER (PARTITION BY e.department_id ORDER BY e.salary) as drankFROM employees e, departments dWHERE e.department_id = d.department_idAND d.department_id IN ('60', '90');& DEPARTMENT_ID LAST_NAME SALARY DRANK------------- ------------------------- ---------- ----------60 Lorentz 4200 160 Austin 4800 260 Pataballa 4800 260 Ernst 6000 360 Hunold 9000 490 Kochhar 17000 190 De Haan 17000 190 King 24000 277。FIRST& 功能描述：从DENSE_RANK返回的集合中取出排在最前面的一个值的行（可能多行，因为值可能相等），因此完整的语法需要在开始处加上一个集合函数以从中取出记录SAMPLE：下面例子中DENSE_RANK按部门分区，再按佣金commission_pct排序，FIRST取出佣金最低的对应的所有行，然后前面的MAX函数从这个集合中取出薪水最低的值；LAST取出佣金最高的对应的所有行，然后前面的MIN函数从这个集合中取出薪水最高的值SELECT last_name, department_id, salary,MIN(salary) KEEP (DENSE_RANK FIRST ORDER BY commission_pct)OVER (PARTITION BY department_id) "Worst",MAX(salary) KEEP (DENSE_RANK LAST ORDER BY commission_pct)OVER (PARTITION BY department_id) "Best"FROM employees& WHERE department_id in (20,80)& ORDER BY department_id,LAST_NAME DEPARTMENT_ID SALARY Worst Best------------------------- ------------- ---------- ---------- ----------Fay 20 000Hartstein 20
13000Kumar 80 000Banda 80 000Johnson 80 000Ande 80 000Lee 80 000Tuvault 80 000Sewall 80 000Marvins 80 000Bates 80 000...78。FIRST_VALUE& 功能描述：返回组中数据窗口的第一个值。SAMPLE：下面例子计算按部门分区按薪水排序的数据窗口的第一个值对应的名字，如果薪水的第一个值有多个，则从多个对应的名字中取缺省排序的第一个名字SELECT department_id, last_name, salary, FIRST_VALUE(last_name)OVER (PARTITION BY department_id ORDER BY salary ASC ) AS lowest_salFROM employees& WHERE department_id in(20,30);DEPARTMENT_ID LAST_NAME SALARY LOWEST_SAL------------- ------------------------- ---------- --------------20 Fay 6000 Fay20 Hartstein 13000 Fay30 Colmenares 2500 Colmenares30 Himuro 2600 Colmenares30 Tobias 2800 Colmenares30 Baida 2900 Colmenares30 Khoo 3100 Colmenares30 Raphaely 11000 Colmenares79。LAG& 功能描述：可以访问结果集中的其它行而不用进行自连接。它允许去处理游标，就好像游标是一个数组一样。在给定组中可参考当前行之前的行，这样就可以从组中与当前行一起选择以前的行。Offset是一个正整数，其默认值为1，若索引超出窗口的范围，就返回默认值（默认返回的是组中第一行），其相反的函数是LEADSAMPLE：下面的例子中列prev_sal返回按hire_date排序的前1行的salary值SELECT last_name, hire_date, salary,LAG(salary, 1, 0) OVER (ORDER BY hire_date) AS prev_salFROM employeesWHERE job_id = 'PU_CLERK';LAST_NAME HIRE_DATE SALARY PREV_SAL------------------------- ---------- ---------- ----------Khoo 18-5月 -95 3100 0Tobias 24-7月 -97 Baida 24-12月-97 Himuro 15-11月-98 Colmenares 10-8月 -99 • 80。LAST& 功能描述：从DENSE_RANK返回的集合中取出排在最后面的一个值的行（可能多行，因为值可能相等），因此完整的语法需要在开始处加上一个集合函数以从中取出记录SAMPLE：下面例子中DENSE_RANK按部门分区，再按佣金commission_pct排序，FIRST取出佣金最低的对应的所有行，然后前面的MAX函数从这个集合中取出薪水最低的值；LAST取出佣金最高的对应的所有行，然后前面的MIN函数从这个集合中取出薪水最高的值SELECT last_name, department_id, salary,MIN(salary) KEEP (DENSE_RANK FIRST ORDER BY commission_pct)OVER (PARTITION BY department_id) "Worst",MAX(salary) KEEP (DENSE_RANK LAST ORDER BY commission_pct)OVER (PARTITION BY department_id) "Best"FROM employees& WHERE department_id in (20,80)& ORDER BY department_id,LAST_NAME DEPARTMENT_ID SALARY Worst Best------------------------- ------------- ---------- ---------- ----------Fay 20 000Hartstein 20
13000Kumar 80 000Banda 80 000Johnson 80 000Ande 80 000Lee 80 000Tuvault 80 000Sewall 80 000Marvins 80 000Bates 80 000.81。LAST_VALUE& 功能描述：返回组中数据窗口的最后一个值。SAMPLE：下面例子计算按部门分区按薪水排序的数据窗口的最后一个值对应的名字，如果薪水的最后一个值有多个，则从多个对应的名字中取缺省排序的最后一个名字SELECT department_id, last_name, salary, LAST_VALUE(last_name)OVER(PARTITION BY department_id ORDER BY salary) AS highest_salFROM employees& WHERE department_id in(20,30);DEPARTMENT_ID LAST_NAME SALARY HIGHEST_SAL------------- ------------------------- ---------- ------------20 Fay 6000 Fay20 Hartstein 13000 Hartstein30 Colmenares 2500 Colmenares30 Himuro 2600 Himuro30 Tobias 2800 Tobias30 Baida 2900 Baida30 Khoo 3100 Khoo30 Raphaely 11000 Raphaely82。LEAD& 功能描述：LEAD与LAG相反，LEAD可以访问组中当前行之后的行。Offset是一个正整数，其默认值为1，若索引超出窗口的范围，就返回默认值（默认返回的是组中第一行）SAMPLE：下面的例子中每行的"NextHired"返回按hire_date排序的下一行的hire_date值SELECT last_name, hire_date,& LEAD(hire_date, 1) OVER (ORDER BY hire_date) AS "NextHired"& FROM employees WHERE department_id = 30;LAST_NAME HIRE_DATE NextHired------------------------- --------- ---------Raphaely 07-DEC-94 18-MAY-95Khoo 18-MAY-95 24-JUL-97Tobias 24-JUL-97 24-DEC-97Baida 24-DEC-97 15-NOV-98Himuro 15-NOV-98 10-AUG-99Colmenares 10-AUG-9983。MAX& 功能描述：在一个组中的数据窗口中查找表达式的最大值。SAMPLE：下面例子中dept_max返回当前行所在部门的最大薪水值SELECT department_id, last_name, salary,& MAX(salary) OVER (PARTITION BY department_id) AS dept_maxFROM employees WHERE department_id in (10,20,30);DEPARTMENT_ID LAST_NAME SALARY DEPT_MAX------------- ------------------------- ---------- ----------10 Whalen 20 Hartstein 20 Fay 30 Raphaely 30 Khoo 30 Baida 30 Tobias 30 Himuro 30 Colmenares 84。MIN& 功能描述：在一个组中的数据窗口中查找表达式的最小值。SAMPLE：下面例子中dept_min返回当前行所在部门的最小薪水值SELECT department_id, last_name, salary,& MIN(salary) OVER (PARTITION BY department_id) AS dept_minFROM employees WHERE department_id in (10,20,30);DEPARTMENT_ID LAST_NAME SALARY DEPT_MIN------------- ------------------------- ---------- ----------10 Whalen 20 Hartstein 20 Fay 30 Raphaely 30 Khoo 30 Baida 30 Tobias 30 Himuro 30 Colmenares 85。NTILE& 功能描述：将一个组分为"表达式"的散列表示，例如，如果表达式=4，则给组中的每一行分配一个数（从1到4），如果组中有20行，则给前5行分配1，给下5行分配2等等。如果组的基数不能由表达式值平均分开，则对这些行进行分配时，组中就没有任何percentile的行数比其它percentile的行数超过一行，最低的percentile是那些拥有额外行的percentile。例如，若表达式=4，行数=21，则percentile=1的有5行，percentile=2的有5行等等。SAMPLE：下例中把6行数据分为4份SELECT last_name, salary,& NTILE(4) OVER (ORDER BY salary DESC) AS quartile FROM employeesWHERE department_id = 100;LAST_NAME SALARY QUARTILE------------------------- ---------- ----------Greenberg 12000 1Faviet 9000 1Chen 8200 2Urman 7800 2Sciarra 7700 3Popp 6900 486。PERCENT_RANK& 功能描述：和CUME_DIST（累积分配）函数类似，对于一个组中给定的行来说，在计算那行的序号时，先减1，然后除以n-1（n为组中所有的行数）。该函数总是返回0～1（包括1）之间的数。SAMPLE：下例中如果Khoo的salary为2900，则pr值为0.6，因为RANK函数对于等值的返回序列值是一样的SELECT department_id, last_name, salary,& PERCENT_RANK()& OVER (PARTITION BY department_id ORDER BY salary) AS prFROM employeesWHERE department_id & 50ORDER BY department_id,DEPARTMENT_ID LAST_NAME SALARY PR------------- ------------------------- ---------- ----------10 Whalen 4400 020 Fay 6000 020 Hartstein 13000 130 Colmenares 2500 030 Himuro 30 Tobias 30 Baida 30 Khoo 30 Raphaely 11000 140 Mavris 6500 0• 87。PERCENTILE_CONT& 功能描述：返回一个与输入的分布百分比值相对应的数据值，分布百分比的计算方法见函数PERCENT_RANK，如果没有正好对应的数据值，就通过下面算法来得到值：RN = 1+ (P*(N-1)) 其中P是输入的分布百分比值，N是组内的行数CRN = CEIL(RN) FRN = FLOOR(RN)if (CRN = FRN = RN) then& (value of expression from row at RN)else(CRN - RN) * (value of expression for row at FRN) +(RN - FRN) * (value of expression for row at CRN)注意：本函数与PERCENTILE_DISC的区别在找不到对应的分布值时返回的替代值的计算方法不同SAMPLE：在下例中，对于部门60的Percentile_Cont值计算如下：P=0.7 N=5 RN =1+ (P*(N-1)=1+(0.7*(5-1))=3.8 CRN = CEIL(3.8)=4& FRN = FLOOR(3.8)=3& （4 - 3.8）* 4800 + (3.8 - 3) * 6000 = 5760SELECT last_name, salary, department_id,PERCENTILE_CONT(0.7) WITHIN GROUP (ORDER BY salary)& OVER (PARTITION BY department_id) "Percentile_Cont",PERCENT_RANK()& OVER (PARTITION BY department_id ORDER BY salary) "Percent_Rank"FROM employees WHERE department_id IN (30, 60);LAST_NAME SALARY DEPARTMENT_ID Percentile_Cont Percent_Rank------------------------- ---------- ------------- --------------- ------------Colmenares 0 0Himuro 0 0.2Tobias 0 0.4Baida 0 0.6Khoo 0 0.8Raphaely 0 1Lorentz 0 0Austin 0 0.25Pataballa 0 0.25Ernst 0 0.75Hunold 0 188。PERCENTILE_DISC& 功能描述：返回一个与输入的分布百分比值相对应的数据值，分布百分比的计算方法见函数CUME_DIST，如果没有正好对应的数据值，就取大于该分布值的下一个值。注意：本函数与PERCENTILE_CONT的区别在找不到对应的分布值时返回的替代值的计算方法不同SAMPLE：下例中0.7的分布值在部门30中没有对应的Cume_Dist值，所以就取下一个分布值0.所对应的SALARY来替代SELECT last_name, salary, department_id,PERCENTILE_DISC(0.7) WITHIN GROUP (ORDER BY salary )OVER (PARTITION BY department_id) "Percentile_Disc",CUME_DIST() OVER (PARTITION BY department_id ORDER BY salary) "Cume_Dist"FROM employees& WHERE department_id in (30, 60);LAST_NAME SALARY DEPARTMENT_ID Percentile_Disc Cume_Dist------------------------- ---------- ------------- --------------- ----------Colmenares 0 .Himuro 0 .Tobias 0 .5Baida 0 .Khoo 0 .Raphaely 0 1Lorentz 0 .2Austin 0 .6Pataballa 0 .6Ernst 0 .8Hunold 0 1& 89。RANK& 功能描述：根据ORDER BY子句中表达式的值，从查询返回的每一行，计算它们与其它行的相对位置。组内的数据按ORDER BY子句排序，然后给每一行赋一个号，从而形成一个序列，该序列从1开始，往后累加。每次ORDER BY表达式的值发生变化时，该序列也随之增加。有同样值的行得到同样的数字序号（认为null时相等的）。然而，如果两行的确得到同样的排序，则序数将随后跳跃。若两行序数为1，则没有序数2，序列将给组中的下一行分配值3，DENSE_RANK则没有任何跳跃。SAMPLE：下例中计算每个员工按部门分区再按薪水排序，依次出现的序列号（注意与DENSE_RANK函数的区别）SELECT d.department_id , e.last_name, e.salary, RANK()& OVER (PARTITION BY e.department_id ORDER BY e.salary) as drankFROM employees e, departments dWHERE e.department_id = d.department_idAND d.department_id IN ('60', '90');DEPARTMENT_ID LAST_NAME SALARY DRANK------------- ------------------------- ---------- ----------60 Lorentz 4200 160 Austin 4800 260 Pataballa 4800 260 Ernst 6000 460 Hunold 9000 590 Kochhar 17000 190 De Haan 17000 190 King 24000 390。RATIO_TO_REPORT& 功能描述：该函数计算expression/(sum(expression))的值，它给出相对于总数的百分比，即当前行对sum(expression)的贡献。SAMPLE：下例计算每个员工的工资占该类员工总工资的百分比SELECT last_name, salary, RATIO_TO_REPORT(salary) OVER () AS rrFROM employeesWHERE job_id = 'PU_CLERK';LAST_NAME SALARY RR------------------------- ---------- ----------Khoo 583Baida 094Tobias 849Himuro 36Colmenares 115• 91。REGR_ (Linear Regression) Functions& 功能描述：这些线性回归函数适合最小二乘法回归线，有9个不同的回归函数可使用。REGR_SLOPE：返回斜率，等于COVAR_POP(expr1, expr2) / VAR_POP(expr2)REGR_INTERCEPT：返回回归线的y截距，等于AVG(expr1) - REGR_SLOPE(expr1, expr2) * AVG(expr2)REGR_COUNT：返回用于填充回归线的非空数字对的数目REGR_R2：返回回归线的决定系数，计算式为：If VAR_POP(expr2) = 0 then return NULLIf VAR_POP(expr1) = 0 and VAR_POP(expr2) != 0 then return 1If VAR_POP(expr1) & 0 and VAR_POP(expr2 != 0 then& return POWER(CORR(expr1,expr),2)REGR_AVGX：计算回归线的自变量(expr2)的平均值，去掉了空对(expr1, expr2)后，等于AVG(expr2)REGR_AVGY：计算回归线的应变量(expr1)的平均值，去掉了空对(expr1, expr2)后，等于AVG(expr1)REGR_SXX： 返回值等于REGR_COUNT(expr1, expr2) * VAR_POP(expr2)REGR_SYY： 返回值等于REGR_COUNT(expr1, expr2) * VAR_POP(expr1)REGR_SXY: 返回值等于REGR_COUNT(expr1, expr2) * COVAR_POP(expr1, expr2)（下面的例子都是在SH用户下完成的）SAMPLE 1：下例计算1998年最后三个星期中两种产品（260和270）在周末的销售量中已开发票数量和总数量的累积斜率和回归线的截距SELECT t.fiscal_month_number "Month", t.day_number_in_month "Day",& REGR_SLOPE(s.amount_sold, s.quantity_sold)& OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month) AS CUM_SLOPE,REGR_INTERCEPT(s.amount_sold, s.quantity_sold)& OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month) AS CUM_ICPT& FROM sales s, times tWHERE s.time_id = t.time_id& AND s.prod_id IN (270, 260)AND t.fiscal_year=1998& AND t.fiscal_week_number IN (50, 51, 52)AND t.day_number_in_week IN (6,7)ORDER BY t.fiscal_month_desc, t.day_number_in_Month Day CUM_SLOPE CUM_ICPT---------- ---------- ---------- ----------12 12 -68 187212 12 -68 187212 13 -20.4.3673512 13 -20.4.3673512 19 -18.712 20 62..2865512 20 62..2865512 20 62..2865512 20 62..2865512 26 67..971231312 26 67..971231312 27 37..95822112 27 37..95822112 27 37..958221SAMPLE 2：下例计算1998年4月每天的累积交易数量SELECT UNIQUE t.day_number_in_month,REGR_COUNT(s.amount_sold, s.quantity_sold)& OVER (PARTITION BY t.fiscal_month_number ORDER BY t.day_number_in_month)"Regr_Count"FROM sales s, times tWHERE s.time_id = t.time_id& AND t.fiscal_year = 1998 AND t.fiscal_month_number = 4;DAY_NUMBER_IN_MONTH Regr_Count------------------- ----------1 8252 16503 24754 330026 2145030 22200SAMPLE 3：下例计算1998年每月销售量中已开发票数量和总数量的累积回归线决定系数SELECT t.fiscal_month_number,REGR_R2(SUM(s.amount_sold), SUM(s.quantity_sold))OVER (ORDER BY t.fiscal_month_number) "Regr_R2"FROM sales s, times tWHERE s.time_id = t.time_idAND t.fiscal_year = 1998GROUP BY t.fiscal_month_numberORDER BY t.fiscal_month_FISCAL_MONTH_NUMBER Regr_R2------------------- ----------12 13 .4 .5 .6 .7 .8 .9 .10 .11 .12 .SAMPLE 4：下例计算1998年12月最后两周产品260的销售量中已开发票数量和总数量的累积平均值SELECT t.day_number_in_month,REGR_AVGY(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month)"Regr_AvgY",REGR_AVGX(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month)"Regr_AvgX"FROM sales s, times tWHERE s.time_id = t.time_id& AND s.prod_id = 260AND t.fiscal_month_desc = '1998-12'AND t.fiscal_week_number IN (51, 52)ORDER BY t.day_number_in_DAY_NUMBER_IN_MONTH Regr_AvgY Regr_AvgX------------------- ---------- ----------14 882 24.514 882 24.515 801 22.2515 801 22.2516 777.6 21.618 642..857142918 642..857142920 589.5 16.37521 544 15.111111122 592..454545522 592..454545524 553..384615424 553..384615426 522 14.527 578.4 16.0666667SAMPLE 5：下例计算产品260和270在1998年2月周末销售量中已开发票数量和总数量的累积REGR_SXY, REGR_SXX, and REGR_SYY统计值SELECT t.day_number_in_month,REGR_SXY(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_year, t.fiscal_month_desc) "Regr_sxy",REGR_SYY(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_year, t.fiscal_month_desc) "Regr_syy",REGR_SXX(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_year, t.fiscal_month_desc) "Regr_sxx"FROM sales s, times tWHERE s.time_id = t.time_id& AND prod_id IN (270, 260)AND t.fiscal_month_desc = '1998-02'AND t.day_number_in_week IN (6,7)ORDER BY t.day_number_in_DAY_NUMBER_IN_MONTH Regr_sxy Regr_syy Regr_sxx------------------- ---------- ---------- ----------1 .41 .41 .41 .47 .48 .414 .415 .421 .422 .4
&92。ROW_NUMBER& 功能描述：返回有序组中一行的偏移量，从而可用于按特定标准排序的行号。SAMPLE：下例返回每个员工再在每个部门中按员工号排序后的顺序号SELECT department_id, last_name, employee_id, ROW_NUMBER()OVER (PARTITION BY department_id ORDER BY employee_id) AS emp_idFROM employeesWHERE department_id & 50;DEPARTMENT_ID LAST_NAME EMPLOYEE_ID EMP_ID------------- ------------------------- ----------- ----------10 Whalen 200 120 Hartstein 201 120 Fay 202 230 Raphaely 114 130 Khoo 115 230 Baida 116 330 Tobias 117 430 Himuro 118 530 Colmenares 119 640 Mavris 203 193。STDDEV& 功能描述：计算当前行关于组的标准偏离。（Standard Deviation）SAMPLE：下例返回部门30按雇佣日期排序的薪水值的累积标准偏离SELECT last_name, hire_date,salary,& STDDEV(salary) OVER (ORDER BY hire_date) "StdDev"FROM employees& WHERE department_id = 30;LAST_NAME HIRE_DATE SALARY StdDev------------------------- ---------- ---------- ----------Raphaely 07-12月-94 11000 0Khoo 18-5月 -95 357Tobias 24-7月 -97 96Baida 24-12月-97 125Himuro 15-11月-98 65Colmenares 10-8月 -99 82994。STDDEV_POP& 功能描述：该函数计算总体标准偏离，并返回总体变量的平方根，其返回值与VAR_POP函数的平方根相同。（Standard Deviation－Population）SAMPLE：下例返回部门20、30、60的薪水值的总体标准偏差SELECT department_id, last_name, salary,& STDDEV_POP(salary) OVER (PARTITION BY department_id) AS pop_stdFROM employeesWHERE department_id in (20,30,60);DEPARTMENT_ID LAST_NAME SALARY POP_STD------------- ------------------------- ---------- ----------20 Hartstein 20 Fay 30 Raphaely .609130 Khoo 9130 Baida 9130 Colmenares 9130 Himuro 9130 Tobias 9160 Hunold 40160 Ernst 40160 Austin 40160 Pataballa 40160 Lorentz 401
95。STDDEV_SAMP& 功能描述： 该函数计算累积样本标准偏离，并返回总体变量的平方根，其返回值与VAR_POP函数的平方根相同。（Standard Deviation－Sample）SAMPLE：下例返回部门20、30、60的薪水值的样本标准偏差SELECT department_id, last_name, hire_date, salary,& STDDEV_SAMP(salary) OVER& (PARTITION BY department_id ORDER BY hire_date& ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS cum_sdev& FROM employeesWHERE department_id in (20,30,60);DEPARTMENT_ID LAST_NAME HIRE_DATE SALARY CUM_SDEV------------- ------------------------- ---------- ---------- ----------20 Hartstein 17-2月 -96 1300020 Fay 17-8月 -97 74730 Raphaely 07-12月-94 1100030 Khoo 18-5月 -95 35730 Tobias 24-7月 -97 9630 Baida 24-12月-97 12530 Himuro 15-11月-98 6530 Colmenares 10-8月 -99 82960 Hunold 03-1月 -90 900060 Ernst 21-5月 -91 03460 Austin 25-6月 -97 07760 Pataballa 05-2月 -98 27660 Lorentz 07-2月 -99 67896。SUM& 功能描述：该函数计算组中表达式的累积和。SAMPLE：下例计算同一经理下员工的薪水累积值SELECT manager_id, last_name, salary,SUM (salary) OVER (PARTITION BY manager_id ORDER BY salaryRANGE UNBOUNDED PRECEDING) l_csumFROM employeesWHERE manager_id in (101,103,108);MANAGER_ID LAST_NAME SALARY L_CSUM---------- ------------------------- ---------- ----------101 Whalen 101 Mavris 101 Baer 101 Greenberg 101 Higgins 103 Lorentz 103 Austin 103 Pataballa 103 Ernst 108 Popp 108 Sciarra 108 Urman 108 Chen 108 Faviet 97。VAR_POP功能描述：（Variance Population）该函数返回非空集合的总体变量（忽略null），VAR_POP进行如下计算：(SUM(expr2) - SUM(expr)2 / COUNT(expr)) / COUNT(expr)SAMPLE：下例计算1998年每月销售的累积总体和样本变量（本例在SH用户下运行）SELECT t.calendar_month_desc,VAR_POP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Pop",VAR_SAMP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Samp"& FROM sales s, times tWHERE s.time_id = t.time_id AND t.calendar_year = 1998GROUP BY t.calendar_month_CALENDAR Var_Pop Var_Samp-------- ---------- ----------..2264E+12..0587E+11..2572E+11..9405E+12..8453E+12..3708E+12..3260E+12..0222E+12..8159E+12..7669E+12..3386E+12• 98。VAR_SAMP& 功能描述：（Variance Sample）该函数返回非空集合的样本变量（忽略null），VAR_POP进行如下计算：(SUM(expr*expr)-SUM(expr)*SUM(expr)/COUNT(expr))/(COUNT(expr)-1)SAMPLE：下例计算1998年每月销售的累积总体和样本变量SELECT t.calendar_month_desc,VAR_POP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Pop",VAR_SAMP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Samp"& FROM sales s, times tWHERE s.time_id = t.time_id AND t.calendar_year = 1998GROUP BY t.calendar_month_CALENDAR Var_Pop Var_Samp-------- ---------- ----------..2264E+12..0587E+11..2572E+11..9405E+12..8453E+12..3708E+12..3260E+12..0222E+12..8159E+12..7669E+12..3386E+1299。VARIANCE& 功能描述：该函数返回表达式的变量，Oracle计算该变量如下：如果表达式中行数为1，则返回0如果表达式中行数大于1，则返回VAR_SAMPSAMPLE：下例返回部门30按雇佣日期排序的薪水值的累积变化SELECT last_name, salary, VARIANCE(salary)& OVER (ORDER BY hire_date) "Variance"FROM employees& WHERE department_id = 30;LAST_NAME SALARY Variance------------------------- ---------- ----------Raphaely 11000 0Khoo 0Tobias 3.3Baida 3.3Himuro 0Colmenares 0100。RANK& 功能描述：根据ORDER BY子句中表达式的值，从查询返回的每一行，计算它们与其它行的相对位置。组内的数据按ORDER BY子句排序，然后给每一行赋一个号，从而形成一个序列，该序列从1开始，往后累加。每次ORDER BY表达式的值发生变化时，该序列也随之增加。有同样值的行得到同样的数字序号（认为null时相等的）。然而，如果两行的确得到同样的排序，则序数将随后跳跃。若两行序数为1，则没有序数2，序列将给组中的下一行分配值3，DENSE_RANK则没有任何跳跃。SAMPLE：下例中计算每个员工按部门分区再按薪水排序，依次出现的序列号（注意与DENSE_RANK函数的区别）SELECT d.department_id , e.last_name, e.salary, RANK()& OVER (PARTITION BY e.department_id ORDER BY e.salary) as drankFROM employees e, departments dWHERE e.department_id = d.department_idAND d.department_id IN ('60', '90');DEPARTMENT_ID LAST_NAME SALARY DRANK------------- ------------------------- ---------- ----------60 Lorentz 4200 160 Austin 4800 260 Pataballa 4800 260 Ernst 6000 460 Hunold 9000 590 Kochhar 17000 190 De Haan 17000 190 King 24000 3101。RATIO_TO_REPORT& 功能描述：该函数计算expression/(sum(expression))的值，它给出相对于总数的百分比，即当前行对sum(expression)的贡献。SAMPLE：下例计算每个员工的工资占该类员工总工资的百分比SELECT last_name, salary, RATIO_TO_REPORT(salary) OVER () AS rrFROM employeesWHERE job_id = 'PU_CLERK';LAST_NAME SALARY RR------------------------- ---------- ----------Khoo 583Baida 094Tobias 849Himuro 36Colmenares 115&#。REGR_ (Linear Regression) Functions& 功能描述：这些线性回归函数适合最小二乘法回归线，有9个不同的回归函数可使用。REGR_SLOPE：返回斜率，等于COVAR_POP(expr1, expr2) / VAR_POP(expr2)REGR_INTERCEPT：返回回归线的y截距，等于AVG(expr1) - REGR_SLOPE(expr1, expr2) * AVG(expr2)REGR_COUNT：返回用于填充回归线的非空数字对的数目REGR_R2：返回回归线的决定系数，计算式为：If VAR_POP(expr2) = 0 then return NULLIf VAR_POP(expr1) = 0 and VAR_POP(expr2) != 0 then return 1If VAR_POP(expr1) & 0 and VAR_POP(expr2 != 0 then& return POWER(CORR(expr1,expr),2)REGR_AVGX：计算回归线的自变量(expr2)的平均值，去掉了空对(expr1, expr2)后，等于AVG(expr2)REGR_AVGY：计算回归线的应变量(expr1)的平均值，去掉了空对(expr1, expr2)后，等于AVG(expr1)REGR_SXX： 返回值等于REGR_COUNT(expr1, expr2) * VAR_POP(expr2)REGR_SYY： 返回值等于REGR_COUNT(expr1, expr2) * VAR_POP(expr1)REGR_SXY: 返回值等于REGR_COUNT(expr1, expr2) * COVAR_POP(expr1, expr2)（下面的例子都是在SH用户下完成的）SAMPLE 1：下例计算1998年最后三个星期中两种产品（260和270）在周末的销售量中已开发票数量和总数量的累积斜率和回归线的截距SELECT t.fiscal_month_number "Month", t.day_number_in_month "Day",& REGR_SLOPE(s.amount_sold, s.quantity_sold)& OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month) AS CUM_SLOPE,REGR_INTERCEPT(s.amount_sold, s.quantity_sold)& OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month) AS CUM_ICPT& FROM sales s, times tWHERE s.time_id = t.time_id& AND s.prod_id IN (270, 260)AND t.fiscal_year=1998& AND t.fiscal_week_number IN (50, 51, 52)AND t.day_number_in_week IN (6,7)ORDER BY t.fiscal_month_desc, t.day_number_in_Month Day CUM_SLOPE CUM_ICPT---------- ---------- ---------- ----------12 12 -68 187212 12 -68 187212 13 -20.4.3673512 13 -20.4.3673512 19 -18.712 20 62..2865512 20 62..2865512 20 62..2865512 20 62..2865512 26 67..971231312 26 67..971231312 27 37..95822112 27 37..95822112 27 37..958221SAMPLE 2：下例计算1998年4月每天的累积交易数量SELECT UNIQUE t.day_number_in_month,REGR_COUNT(s.amount_sold, s.quantity_sold)& OVER (PARTITION BY t.fiscal_month_number ORDER BY t.day_number_in_month)"Regr_Count"FROM sales s, times tWHERE s.time_id = t.time_id& AND t.fiscal_year = 1998 AND t.fiscal_month_number = 4;DAY_NUMBER_IN_MONTH Regr_Count------------------- ----------1 8252 16503 24754 3300.26 2145030 22200SAMPLE 3：下例计算1998年每月销售量中已开发票数量和总数量的累积回归线决定系数SELECT t.fiscal_month_number,REGR_R2(SUM(s.amount_sold), SUM(s.quantity_sold))OVER (ORDER BY t.fiscal_month_number) "Regr_R2"FROM sales s, times tWHERE s.time_id = t.time_idAND t.fiscal_year = 1998GROUP BY t.fiscal_month_numberORDER BY t.fiscal_month_FISCAL_MONTH_NUMBER Regr_R2------------------- ----------12 13 .4 .5 .6 .7 .8 .9 .10 .11 .12 .SAMPLE 4：下例计算1998年12月最后两周产品260的销售量中已开发票数量和总数量的累积平均值SELECT t.day_number_in_month,REGR_AVGY(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month)"Regr_AvgY",REGR_AVGX(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_month_desc, t.day_number_in_month)"Regr_AvgX"FROM sales s, times tWHERE s.time_id = t.time_id& AND s.prod_id = 260AND t.fiscal_month_desc = '1998-12'AND t.fiscal_week_number IN (51, 52)ORDER BY t.day_number_in_DAY_NUMBER_IN_MONTH Regr_AvgY Regr_AvgX------------------- ---------- ----------14 882 24.514 882 24.515 801 22.2515 801 22.2516 777.6 21.618 642..857142918 642..857142920 589.5 16.37521 544 15.111111122 592..454545522 592..454545524 553..384615424 553..384615426 522 14.527 578.4 16.0666667SAMPLE 5：下例计算产品260和270在1998年2月周末销售量中已开发票数量和总数量的累积REGR_SXY, REGR_SXX, and REGR_SYY统计值SELECT t.day_number_in_month,REGR_SXY(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_year, t.fiscal_month_desc) "Regr_sxy",REGR_SYY(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_year, t.fiscal_month_desc) "Regr_syy",REGR_SXX(s.amount_sold, s.quantity_sold)OVER (ORDER BY t.fiscal_year, t.fiscal_month_desc) "Regr_sxx"FROM sales s, times tWHERE s.time_id = t.time_id& AND prod_id IN (270, 260)AND t.fiscal_month_desc = '1998-02'AND t.day_number_in_week IN (6,7)ORDER BY t.day_number_in_DAY_NUMBER_IN_MONTH Regr_sxy Regr_syy Regr_sxx------------------- ---------- ---------- ----------1 .41 .41 .41 .47 .48 .414 .415 .421 .422 .4&#。ROW_NUMBER& 功能描述：返回有序组中一行的偏移量，从而可用于按特定标准排序的行号。SAMPLE：下例返回每个员工再在每个部门中按员工号排序后的顺序号SELECT department_id, last_name, employee_id, ROW_NUMBER()OVER (PARTITION BY department_id ORDER BY employee_id) AS emp_idFROM employeesWHERE department_id & 50;DEPARTMENT_ID LAST_NAME EMPLOYEE_ID EMP_ID------------- ------------------------- ----------- ----------10 Whalen 200 120 Hartstein 201 120 Fay 202 230 Raphaely 114 130 Khoo 115 230 Baida 116 330 Tobias 117 430 Himuro 118 530 Colmenares 119 640 Mavris 203 1104。STDDEV& 功能描述：计算当前行关于组的标准偏离。（Standard Deviation）SAMPLE：下例返回部门30按雇佣日期排序的薪水值的累积标准偏离SELECT last_name, hire_date,salary,& STDDEV(salary) OVER (ORDER BY hire_date) "StdDev"FROM employees& WHERE department_id = 30;LAST_NAME HIRE_DATE SALARY StdDev------------------------- ---------- ---------- ----------Raphaely 07-12月-94 11000 0Khoo 18-5月 -95 357Tobias 24-7月 -97 96Baida 24-12月-97 125Himuro 15-11月-98 65Colmenares 10-8月 -99 829105。STDDEV_POP& 功能描述：该函数计算总体标准偏离，并返回总体变量的平方根，其返回值与VAR_POP函数的平方根相同。（Standard Deviation－Population）SAMPLE：下例返回部门20、30、60的薪水值的总体标准偏差SELECT department_id, last_name, salary,& STDDEV_POP(salary) OVER (PARTITION BY department_id) AS pop_stdFROM employeesWHERE department_id in (20,30,60);DEPARTMENT_ID LAST_NAME SALARY POP_STD------------- ------------------------- ---------- ----------20 Hartstein 20 Fay 30 Raphaely .609130 Khoo 9130 Baida 9130 Colmenares 9130 Himuro 9130 Tobias 9160 Hunold 40160 Ernst 40160 Austin 40160 Pataballa 40160 Lorentz 401106。STDDEV_SAMP& 功能描述： 该函数计算累积样本标准偏离，并返回总体变量的平方根，其返回值与VAR_POP函数的平方根相同。（Standard Deviation－Sample）SAMPLE：下例返回部门20、30、60的薪水值的样本标准偏差SELECT department_id, last_name, hire_date, salary,& STDDEV_SAMP(salary) OVER& (PARTITION BY department_id ORDER BY hire_date& ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS cum_sdev& FROM employeesWHERE department_id in (20,30,60);DEPARTMENT_ID LAST_NAME HIRE_DATE SALARY CUM_SDEV------------- ------------------------- ---------- ---------- ----------20 Hartstein 17-2月 -96 1300020 Fay 17-8月 -97 74730 Raphaely 07-12月-94 1100030 Khoo 18-5月 -95 35730 Tobias 24-7月 -97 9630 Baida 24-12月-97 12530 Himuro 15-11月-98 6530 Colmenares 10-8月 -99 82960 Hunold 03-1月 -90 900060 Ernst 21-5月 -91 03460 Austin 25-6月 -97 07760 Pataballa 05-2月 -98 27660 Lorentz 07-2月 -99 678107。SUM& 功能描述：该函数计算组中表达式的累积和。SAMPLE：下例计算同一经理下员工的薪水累积值SELECT manager_id, last_name, salary,SUM (salary) OVER (PARTITION BY manager_id ORDER BY salaryRANGE UNBOUNDED PRECEDING) l_csumFROM employeesWHERE manager_id in (101,103,108);MANAGER_ID LAST_NAME SALARY L_CSUM---------- ------------------------- ---------- ----------101 Whalen 101 Mavris 101 Baer 101 Greenberg 101 Higgins 103 Lorentz 103 Austin 103 Pataballa 103 Ernst 108 Popp 108 Sciarra 108 Urman 108 Chen 108 Faviet 108。VAR_POP功能描述：（Variance Population）该函数返回非空集合的总体变量（忽略null），VAR_POP进行如下计算：(SUM(expr2) - SUM(expr)2 / COUNT(expr)) / COUNT(expr)SAMPLE：下例计算1998年每月销售的累积总体和样本变量（本例在SH用户下运行）SELECT t.calendar_month_desc,VAR_POP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Pop",VAR_SAMP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Samp"& FROM sales s, times tWHERE s.time_id = t.time_id AND t.calendar_year = 1998GROUP BY t.calendar_month_CALENDAR Var_Pop Var_Samp-------- ---------- ----------..2264E+12..0587E+11..2572E+11..9405E+12..8453E+12..3708E+12..3260E+12..0222E+12..8159E+12..7669E+12..3386E+12109。VAR_SAMP& 功能描述：（Variance Sample）该函数返回非空集合的样本变量（忽略null），VAR_POP进行如下计算：(SUM(expr*expr)-SUM(expr)*SUM(expr)/COUNT(expr))/(COUNT(expr)-1)SAMPLE：下例计算1998年每月销售的累积总体和样本变量SELECT t.calendar_month_desc,VAR_POP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Pop",VAR_SAMP(SUM(s.amount_sold))& OVER (ORDER BY t.calendar_month_desc) "Var_Samp"& FROM sales s, times tWHERE s.time_id = t.time_id AND t.calendar_year = 1998GROUP BY t.calendar_month_CALENDAR Var_Pop Var_Samp-------- ---------- ----------..2264E+12..0587E+11..2572E+11..9405E+12..8453E+12..3708E+12..3260E+12..0222E+12..8159E+12..7669E+12..3386E+12110。VARIANCE& 功能描述：该函数返回表达式的变量，Oracle计算该变量如下：如果表达式中行数为1，则返回0如果表达式中行数大于1，则返回VAR_SAMPSAMPLE：下例返回部门30按雇佣日期排序的薪水值的累积变化SELECT last_name, salary, VARIANCE(salary)& OVER (ORDER BY hire_date) "Variance"FROM employees& WHERE department_id = 30;LAST_NAME SALARY Variance------------------------- ---------- ----------Raphaely 11000 0Khoo 0Tobias 3.3Baida 3.3Himuro 0Colmenares 0
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