Oracle11g聚合函数

聚合函数就是基于多行数据返回一行结果，下面就是Oracle提供的一些列聚合函数：

AVG

COLLECT

CORR

CORR_*

COUNT

COVAR_POP

COVAR_SAMP

CUME_DIST

DENSE_RANK

FIRST

GROUP_ID

GROUPING

GROUPING_ID

LAST

LISTAGG

MAX

MEDIAN

MIN

PERCENT_RANK

PERCENTILE_CONT

PERCENTILE_DISC

RANK

REGR_(Linear Regression) Functions

STATS_BINOMIAL_TEST

STATS_CROSSTAB

STATS_F_TEST

STATS_KS_TEST

STATS_MODE

STATS_MW_TEST

STATS_ONE_WAY_ANOVA

STATS_T_TEST_*

STATS_WSR_TEST

STDDEV

STDDEV_POP

STDDEV_SAMP

SUM

SYS_XMLAGG

VAR_ POP

VAR_ SAMP

VARI ANCE

XMLAGG

1、AVG( distinct|all,expr,over(analytic_clause) ) 求平均值

SELECT deptno,AVG(sal) "Average"

From emp

Group By Deptno

order by deptno;

Select Mgr, Ename, Hiredate, Sal,

AVG(sal) OVER (PARTITION BY mgr ORDER BYhiredate ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS c_mavg

From Emp

ORDER BY Mgr, Hiredate, Sal;

2、COLLECT(distinct|unique,column,orderby expr)

将结果转换为一个嵌套表

CREATE TYPE phone_book_t AS TABLE OFphone_list_typ;

/

SELECT CAST(COLLECT(phone_numbers) ASphone_book_t) Phone_Book

FROM customers

ORDER BY phone_book;

3、CORR( expr1,expr2,over(analytic_clause) ) 返回一对表达式的相关系数[返回一个-1~1的数，相关系数给出了关联的强度，0表示不相关]

Select Deptno,CORR(empno,mgr) a1

From Emp

Group By Deptno;

SELECT empno, job,

TO_CHAR((SYSDATE - hiredate) YEAR TO MONTH )"Yrs-Mns", sal,

CORR(SYSDATE-hiredate, sal)

Over(Partition By Job) As"Correlation"

FROM emp

4、CORR_K(expr1,expr2,

COEFFICIENT|ONE_SIDED_SIG|ONE_SIDED_SIG_POS|ONE_SIDED_SIG_NEG|TWO_SIDED_SIG));

CORR_S(expr1,expr2,

COEFFICIENT|ONE_SIDED_SIG|ONE_SIDED_SIG_POS|ONE_SIDED_SIG_NEG|TWO_SIDED_SIG));

COEFFICIENT：相关系数

ONE_SIDED_SIG ：Positive one-tailed significance of the correlation

ONE_SIDED_SIG_POS ：Same as ONE_SIDED_SIG

ONE_SIDED_SIG_NEG ：Negative one-tailed significance of the correlation

TWO_SIDED_SIG ：Two-tailed significanceof the correlation

Select Count(*) Count,

CORR_S(sal, mgr) commission,

CORR_S(sal, Empno) empid

FROM emp;

Select Corr_K(Sal, mgr, 'COEFFICIENT')Coefficient,

Corr_K(Sal, mgr, 'TWO_SIDED_SIG')Two_Sided_P_Value

FROM emp;

5、Count(distinct|all expr) OVER(analytic_clause)

select count(*) a1 from emp;

Select Ename, Sal,

COUNT(*) OVER (ORDER BY sal RANGE BETWEEN 50PRECEDING AND 150 FOLLOWING) AS mov_count

From Emp

ORDER BY sal,ename;

6、COVAR_POP(expr1,expr2)OVER(analytic_clause) 返回一对表达式的协方差[(SUM(expr1 * expr2) - SUM(expr2) * SUM(expr1) / n) / n]

7、COVAR_SAMP(expr1,expr2)OVER(analytic_clause) 返回一对表达式的样本方差[(SUM(expr1 * expr2) - SUM(expr1) * SUM(expr2) / n) / (n-1)]

SELECT job,

COVAR_POP(SYSDATE-hiredate, sal) AS covar_pop,

COVAR_SAMP(SYSDATE-hiredate, sal) AScovar_samp

FROM emp

WHERE 1=1

Group By job

ORDER BY job, covar_pop, covar_samp;

8、CUME_DIST(expr)WITHIN GROUP (ORDER BY expr  DESC|ASC  NULLS  FIRST|LAST)

CUME_DIST() OVER (query_partition_clause order_by_clause)

求累计分布，结果范围(0,1]

Select Cume_Dist(15500, 0.05) Within Group

(Order By Sal, mgr) "Cume-Dist of15500"

From Emp;

SELECT job, ename, sal, CUME_DIST()

Over (Partition By Job Order By Sal) AsCume_Dist

FROM emp

Where 1=1

ORDER BY job, ename, sal, cume_dist;

9、DENSE_RANK(expr)WITHIN GROUP (ORDER BY expr DESC|ASC NULLS FIRST|LAST)

DENSE_RANK() OVER (query_partition_clause order_by_clause)

结果集排序(如果有两个第二名，那么下一个还是第三名)

SELECT DENSE_RANK(15500, 0.05) WITHIN GROUP

(Order By Sal Desc, mgr) "DenseRank"

From Emp;

Select tmp.Dname,tmp.Ename,tmp.Sal,tmp.Drank

From

(

SelectD.Dname, E.Ename, E.Sal, Dense_Rank()

Over(Partition By E.deptno Order By E.Sal) As Drank

FromEmp E, Dept D

WhereE.Deptno = D.Deptno

)Tmp

where 1=1

10、RANK(expr) WITHINGROUP (ORDER BY expr DESC|ASC NULLS FIRST|LAST)

RANK() OVER (query_partition_clause order_by_clause)

结果集排序(如果有两个第二名，那么下一个还是第四名)

SELECT RANK(15500) WITHIN GROUP (Order By SalDesc) "Rank of 15500"

FROM emp;

Select Deptno, Ename, Sal, Mgr,

RANK() OVER (PARTITION BY deptno ORDER BY salDESC, mgr) "Rank"

From emp

Where 1=1

ORDER BY deptno, ename, sal, mgr, "Rank";

11、First

aggregate_function KEEP

(DENSE_RANK FIRST ORDER BY expr DESC|ASCNULLS FIRST|LAST)

OVER (query_partition_clause)

12、LAST

aggregate_function KEEP

(DENSE_RANK LAST ORDER BY expr DESC|ASCNULLS FIRST|LAST)

OVER (query_partition_clause)

Select Deptno,

MIN(sal) KEEP (DENSE_RANK FIRST ORDER BYempno) "Worst",

MAX(sal) KEEP (DENSE_RANK LAST ORDER BY empno)"Best"

From Emp

Group By Deptno

ORDER BY deptno;

Select Deptno,Ename, Sal,

Min(Sal) Keep (Dense_Rank First Order Byename) Over (Partition By deptno) "Worst",

MAX(sal) KEEP (DENSE_RANK LAST ORDER BY ename)OVER (PARTITION BY deptno) "Best"

From Emp

ORDER BY deptno, sal, ename;

13、GROUP_ID() 用于消除GROUP BY子句返回的重复记录。GROUP_ID()不接受任何参数。如果某个特定的分组重复出现n次，那么GROUP_ID()返回从0到n-1之间的一个整数,可以通过 Having GROUP_ID()=0 来消除重复

14、GROUPING(expr) 用于区分常规行与合计(总计)行

GROUPING(expr) 常与 GROUP BY ROLLUP(expr)、GROUP BY CUBE(expr)一起使用

Select deptno,count(empno)a1,GROUP_ID()a2,GROUPING(deptno) a3

From Emp

Group By rollup(deptno)

order by deptno

15、GROUPING_ID(expr) 返回GROUPING位向量的十进制值。GROUPING位向量的计算方法是将按照顺序对每一列调用GROUPING函数的结果组合起来

Select deptno,job,count(empno)a1,GROUP_ID()a2,GROUPING(deptno) a3,GROUPING_ID(deptno,job) a4

From Emp

Group By Rollup(Deptno,Job)

order by deptno,job;

16、LISTAGG(measure_expr, delimiter) WITHIN GROUP (order_by_clause)

OVER (query_partition_clause)字符串聚合(拼接)，这个函数在11G R2中新增，运用很广泛，以前还需要自己写一个拼接的函数

SELECT LISTAGG(ename, '; ') WITHIN GROUP(ORDER BY hiredate, empno) "Emp_list",

MIN(hiredate) "Earliest"

FROM emp

WHERE 1=1;

Select Deptno,

Listagg(ename, '; ') Within Group (Order ByHireDate) "Employees"

FROM emp

Group By deptno

ORDER BY deptno;

在oracle 10G中 可以考虑： WMSYS.WM_CONCAT

17、MAX (DISTINCT|ALL expr) OVER ( analytic_clause ) 返回最大值

18、MIN (DISTINCT|ALL expr) OVER ( analytic_clause ) 返回最小值

Select Deptno,Max(Sal),MIN(sal)

From Emp

group by deptno;

Select Mgr, Ename, Sal,

Max(Sal) Over (Partition By Mgr) As Mgr_Max,

MIN(sal) OVER (PARTITION BY mgr) AS mgr_min

From Emp

ORDER BY mgr, ename, sal;

19、MEDIAN ( expr ) OVER( query_partition_clause ) 返回一组数据的中间值

例如：{1,2,3,4,5} 则返回3，{1,2,3,4}则返回(2+3)/2

with tab as(

Select1 Num From Dual Union All

select3 from dual union all

select20 from dual union all

select12 from dual

)

Select Median(Num) a1 From tab;

SELECT deptno, MEDIAN(sal)

From Emp

Group By Deptno

ORDER BY deptno;

20、PERCENT_RANK ( expr)WITHIN GROUP ( ORDER BY expr DESC|ASC NULLS FIRST|LAST)

PERCENT_RANK ( ) OVER (query_partition_clauseorder_by_clause )

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

SELECT PERCENT_RANK(15000,0.05) WITHIN GROUP(ORDER BY sal,mgr) "Percent-Rank"

From emp;

Select Deptno,Ename,Sal,Percent_Rank()Over(Partition By Deptno Order By Sal) Pr

From Emp

order by deptno,sal;

21、PERCENTILE_CONT (expr ) WITHIN GROUP ( ORDER BY expr DESC|ASC)

OVER ( query_partition_clause )

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同函数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 the result is
   (value of expression from row at RN)
  Otherwisethe result is
   (CRN - RN) * (value of expression for row at FRN) +
   (RN - FRN) * (value of expression for row at CRN)

SELECT deptno,

PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BYsal DESC) "Median cont",

PERCENTILE_DISC(0.5) WITHIN GROUP (ORDER BYsal DESC) "Median disc"

FROM emp

Group By deptno

ORDER BY deptno;

SELECT ename, sal, deptno,

PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BYsal DESC) OVER (PARTITION BY deptno) "Percentile_Cont",

PERCENT_RANK() OVER (PARTITION BY deptno ORDERBY sal DESC) "Percent_Rank"

FROM emp

ORDER BY ename, sal, deptno;

22、PERCENTILE_DISC (expr ) WITHIN GROUP ( ORDER BY expr DESC|ASC)

OVER ( query_partition_clause )

percentile_disc函数在功能上类似于percentile_cont函数，只是percentile_cont函数使用了连续分布模型，而percentile_disc函数使用了离期分布模型。当没有值与指定的percent_rank精确匹配的时候，percentile_cont(0.5)会计算两个离得最近的值的平均值。相反，在升序排列的情况下，percentile_disc函数只取比所传递的参数percent_rank值更大的值。在降序排列的时候，percentile_disc函数只取比所传递的参数percent_rank值更小的值。

Select Ename, Sal, Deptno,

Percentile_Disc(0.5) Within Group (Order BySal Desc) Over (Partition By Deptno) "Percentile_Disc",

CUME_DIST() OVER (PARTITION BY deptno ORDER BYsal DESC) "Cume_Dist"

FROM emp

ORDER BY ename, sal, deptno

23、REGR_ (线性回归) 函数

The linear regression functions are:

■ REGR_SLOPE

■ REGR_INTERCEPT

■ REGR_COUNT

■ REGR_R2

■ REGR_AVGX

■ REGR_AVGY

■ REGR_SXX

■ REGR_SYY

■ REGR_SXY

语法：

fun_name(expr1,expr2) OVER(analytic_clause)

SELECT job, empno ID, sal,

REGR_SLOPE(SYSDATE-hiredate, sal)

OVER (PARTITION BY job) slope,

REGR_INTERCEPT(SYSDATE-hiredate, sal)

Over (Partition By Job) Intcpt,

REGR_R2(SYSDATE-hiredate, sal)

OVER (PARTITION BY job) rsqr,

REGR_COUNT(SYSDATE-hiredate, sal)

OVER (PARTITION BY job) count,

REGR_AVGX(SYSDATE-hiredate, sal)

OVER (PARTITION BY job) avgx,

REGR_AVGY(SYSDATE-hiredate, sal)

OVER (PARTITION BY job) avgy

From Emp

ORDER BY job, empno;

SELECT job,

Regr_Slope(Sysdate-Hiredate, Sal) Slope,

Regr_Intercept(Sysdate-Hiredate, Sal)Intercept

FROM emp

Group By Job

ORDER BY job;

SELECT job,

REGR_COUNT(SYSDATE-hiredate, sal) count

From Emp

Group By Job

ORDER BY job, count;

SELECT job,

Regr_R2(Sysdate-Hiredate, Sal) Regr_R2

FROM emp

Group By Job

ORDER BY job, Regr_R2;

SELECT job,

REGR_AVGY(SYSDATE-hiredate, sal) avgy,

Regr_Avgx(Sysdate-Hiredate, Sal) Avgx

FROM emp

Group By Job

ORDER BY job, avgy, avgx

SELECT job,

REGR_SXY(SYSDATE-hiredate, sal) regr_sxy,

REGR_SXX(SYSDATE-hiredate, sal) regr_sxx,

Regr_Syy(Sysdate-Hiredate, Sal) Regr_Syy

FROM emp

Group By Job

ORDER BY job;

24、STATS_BINOMIAL_TEST( expr1 , expr2 , p,

TWO_SIDED_PROB|EXACT_PROB|ONE_SIDED_PROB_OR_MORE|ONE_SIDED_PROB_OR_LESS)

统计二项测试是一个精确概率测试用于二分变量,那里只有两个可能值存在。它测试一个样品之间的差异比例和给定的比例

25、STATS_CROSSTAB (expr1 , expr2,

CHISQ_OBS|CHISQ_SIG|CHISQ_DF|PHI_COEFFICIENT|CRAMERS_V|CONT_COEFFICIENT|

COHENS_K

)

用于分析两个变量

26、STATS_F_TEST ( expr1, expr2,

[STATISTIC|DF_NUM|DF_DEN|ONE_SIDED_SIG|,expr3] |TWO_SIDED_SIG)

测试两个方差是否有明显的不同

27、STATS_KS_TEST (expr1 , expr2,STATISTIC|SIG)

是柯尔莫哥洛夫斯米尔诺夫函数比较两个样品测试他们是否来自相同的总体或有

相同分布的总体

28、STATS_MODE ( expr )

统计模式需要一组值作为它的参数并且返回发生以最大的频率

Select Deptno, Stats_Mode(Sal)

FROM emp

Group By deptno

ORDER BY deptno, stats_mode(sal);

29、STATS_MW_TEST (expr1 , expr2,STATISTIC|U_STATISTIC|ONE_SIDED_SIG , expr3|

TWO_SIDED_SIG)

一个曼惠特尼测试比较两个独立样本来测试该无效假设,这两个种群具有相同的分布函数与替代并且假设这两个分布函数是不同的

30、STATS_ONE_WAY_ANOVA( expr1 , expr2,

SUM_SQUARES_BETWEEN|SUM_SQUARES_WITHIN|DF_BETWEEN|DF_WITHIN|MEAN_SQUARES_BETWEEN|MEAN_SQUARES_WITHIN|F_RATIO|SIG)

单向方差分析函数(统计一维方差分析)测试差异在意味着(为团体或变量),通过比较两种统计学意义不同的估计方差

31、STATS_T_TEST_*

相关函数:

■ STATS_T_TEST_ONE: A one-sample t-test

■ STATS_T_TEST_PAIRED: A two-sample, paired t-test (also known as acrossed

t-test)

■ STATS_T_TEST_INDEP: A t-test of two independent groups with thesame

variance (pooled variances)

■ STATS_T_TEST_INDEPU: A t-test of two independent groups withunequal

variance (unpooled variances)

语法：

STATS_T_TEST_INDEP|STATS_T_TEST_INDEPU|STATS_T_TEST_ONE|STATS_T_TEST_PAIRED

( expr1 , expr2,

[STATISTIC|ONE_SIDED_SIG|, expr3]|TWO_SIDED_SIG|DF)

32、STATS_WSR_TEST (expr1 , expr2,STATISTIC|ONE_SIDED_SIG|TWO_SIDED_SIG)

33、STDDEV (DISTINCT|ALLexpr ) OVER ( analytic_clause ) 返回样本标准偏差

Select Stddev(Sal) "Deviation"

FROM emp;

Select Ename, Sal,

Stddev(Sal) Over (Order By HireDate)"StdDev"

FROM emp

ORDER BY ename, sal, "StdDev";

34、STDDEV_POP ( expr ) OVER( analytic_clause )

总体标准偏差计算并返回总体方差的平方根

SELECT deptno, ename, sal,

STDDEV_POP(sal) OVER (PARTITION BY deptno) ASpop_std

From emp

ORDER BY deptno, ename, sal, pop_std;

35、STDDEV_SAMP ( expr )OVER ( analytic_clause )

计算累积样本标准偏差和返回样本方差的平方根

Select Deptno, Ename, Hiredate, Sal,

STDDEV_SAMP(sal) OVER (PARTITION BY deptnoORDER BY hiredate ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS cum_sdev

From emp

ORDER BY deptno, ename, hiredate, sal,cum_sdev;

36、SUM (DISTINCT|ALL expr) OVER ( analytic_clause ) 求和

Select Mgr, Ename, Sal,

SUM(sal) OVER (PARTITION BY mgr ORDER BY salRANGE UNBOUNDED PRECEDING) l_csum

From Emp

ORDER BY mgr, ename, sal, l_csum;

37、SYS_XMLAGG ( expr,fmt) 将查询结果生成一个Xml文档

Select Sys_Xmlagg(Sys_Xmlgen(ename)) Xmlagg

FROM emp;

38、VAR_POP ( expr ) OVER ( analytic_clause )

返回总体方差的一组数字[丢弃Null值]

39、VAR_SAMP ( expr ) OVER( analytic_clause )

返回样本方差的一组数字[丢弃Null值]

Select Var_Pop(Sal),Var_SAMP(Sal)

FROM emp;

40、VARIANCE (DISTINCT|ALLexpr ) OVER ( analytic_clause ) 返回回报方差

SELECT ename, sal, VARIANCE(sal) OVER (ORDERBY hiredate) "Variance"

FROM emp

ORDER BY ename, sal, "Variance";

41、XMLAGG (XMLType_instance order_by_clause) 返回Xml文档

Select Xmlelement("Department",Xmlagg(Xmlelement("Employee",E.Job||' '||E.Ename) Order By Ename)) As "Dept_list"

From emp E;

Select Xmlelement("Department",Xmlagg(Xmlelement("Employee",E.Job||' '||E.Ename))) As "Dept_list"

From emp E

GROUP BY e.deptno