Aggregate functions without group by clause
hi friends,
i was asked an interesting question by my friend. The question is...
There is a DEPT table which has dept_no and dept_name. There is an EMP table which has emp_no, emp_name and dept_no.
My requirement is to get the the dept_no, dept_name and the no. of employees in that department. This should be done without using a group by clause.
Can anyone of you help me to get a solution for this?
select distinct emp.deptno,dname
,count(*) over(partition by emp.deptno)
from emp
,dept
where emp.deptno=dept.deptno;
10 ACCOUNTING 3
20 RESEARCH 5
30 SALES 6
Similar Messages
-
Aggregate fuction with group by clause
Hello,
Following is assignment is given but i dont get correct output
so please i am request to all of us write code to solve my problem.
There can be multiple records for one customer in VBAK tables with different combinations.
Considering that we do not need details of each sales order,
use Aggregate functions with GROUP BY clause in SELECT to read the fields.
<garbled code removed>
Moderator Message: Please paste the relevant portions of the code
Edited by: Suhas Saha on Nov 18, 2011 1:48 PMSo if you need not want all the repeated records, then you select all the values to an Internal table,
and declare an internal table of same type and Usee COLLECT
for ex:
itab1 type <xxxx>.
wa_itba like line of itab1.
itab2 type <xxxx>. "<-This should be same type of above.
select * from ..... into table itab1.
and now...
loop at itab1 into wa_itab.
collect wa_itab1 into itab2.
endloop.
then you will get your desired result.. -
Nested Group Function without Group By Problem
Hey everyone,
I have 3 tables as below:
TABLES
ITEM (Item_no, Item_price, desc)
DeliveryItem (delivery_no, item_no, quantity)
Delivery (delivery_no, delivery_date)
SELECT desc, MAX(SUM(quantity)) FROM DeliveryItem, Item, Delivery WHERE Item.item_no = DeliveryItem.item_no AND Delivery.delivery_no = deliveryitem.delivery_no;
And I'm trying to output description of most delivered item but I got an error like SQL Error: ORA-00978: nested group function without GROUP BY. Could you help me to fix my code?
ThanxHi,
DESC is not a good column name; you could get errors if the parser thinks it means DESCending. I used DESCRIPTION instead, below.
I think the best way is to do the SUM in a sub-query, lkike this:
WITH got_r_num AS
SELECT item_no
, SUM (quantity) AS total_quantity
, RANK () OVER (ORDER BY SUM (quantity) DESC) AS r_num
FROM deliveryitem
GROUP BY item_no
SELECT i.description
, r.total_quantity
FROM got_r_num r
JOIN item i ON r.item_no = i.item_no
WHERE r.r_num = 1
;If you want to do it without a sub-query:
SELECT MIN (i.description) KEEP (DENSE_RANK LAST ORDER BY SUM (di.quantity)
AS description
, MAX (SUM (quantity)) AS total_quantity
FROM deliveryitem di
JOIN item i ON d1.item_no = i.tiem_no
GROUP BY i.description
;If you do nested aggegate functions, then every column in the SELECT clause must be an aggregate applied to either
(a) another aggregate, or
(b) one of the GROUP BY expressions.
That's why you got the ORA-00937 error.
This second approach will only display one row of output, so If there is a tie for the item with the greatest total_quantity, only one description will be shown. The RANK method will show all items that had the highest total_quantity.
It looks like the delivery table plays no role in this problem, but it there's some reason for including it, you can join it tpo either query above.
Of course, unless you post test copies of your tables (CREATE TABLE and INSERT statements) I cn't test anything.
Edited by: Frank Kulash on Nov 6, 2010 10:57 AM -
Nested group function without group xmlagg
I am getting nested group function without group by xmlagg when using the xmlagg function inside another xmlagg function. Find the table structure and sample data here,
CREATE TABLE "TEST_TABLE"
("KEY" NUMBER(20,0),
"NAME" VARCHAR2(50 ),
"DESCRIPTION" VARCHAR2(100 )
Insert into TEST_TABLE (KEY,NAME,DESCRIPTION) values (1,'sam','desc1');
Insert into TEST_TABLE (KEY,NAME,DESCRIPTION) values (2,'max','desc2');
Insert into TEST_TABLE (KEY,NAME,DESCRIPTION) values (3,'peter',null);
Insert into TEST_TABLE (KEY,NAME,DESCRIPTION) values (4,'andrew',null);
select
XMLSerialize(document
xmlelement("root",
xmlagg(
xmlelement("emp"
, xmlforest(Key as "ID")
, xmlforest(name as "ename")
, xmlelement("Descriptions",
xmlagg(
xmlforest(description as "Desc")
) as clob indent
) as t
from test_table;Then i removed the xmlagg function from the above select query and used xmlelement instead
select
XMLSerialize(document
xmlelement("root",
xmlagg(
xmlelement("emp"
, xmlforest(Key as "ID")
, xmlforest(name as "ename")
, xmlelement("Descriptions",
xmlforest(description as "Desc")
) as clob indent
) as t
from test_table;This is working fine, but xml created with empty elements for Descriptions element for key 3 and 4 which has null values. I need don't need Descriptions element in the xml when it has null value. Please help me to resolve this.You can do it with a correlated subquery :
SQL> select xmlserialize(document
2 xmlelement("root",
3 xmlagg(
4 xmlelement("emp"
5 , xmlforest(
6 t.key as "ID"
7 , t.name as "ename"
8 , (
9 select xmlagg(
10 xmlelement("Desc", d.description)
11 order by d.description -- if necessary
12 )
13 from test_desc d
14 where d.key = t.key
15 ) as "Descriptions"
16 )
17 )
18 )
19 ) as clob indent
20 )
21 from test_table t;
XMLSERIALIZE(DOCUMENTXMLELEMEN
<root>
<emp>
<ID>1</ID>
<ename>sam</ename>
<Descriptions>
<Desc>desc1_1</Desc>
<Desc>desc1_2</Desc>
<Desc>desc1_3</Desc>
</Descriptions>
</emp>
<emp>
<ID>2</ID>
<ename>max</ename>
<Descriptions>
<Desc>desc2_1</Desc>
<Desc>desc2_2</Desc>
<Desc>desc2_3</Desc>
</Descriptions>
</emp>
<emp>
<ID>3</ID>
<ename>peter</ename>
</emp>
<emp>
<ID>4</ID>
<ename>andrew</ename>
</emp>
</root>
Or an OUTER JOIN + GROUP-BY :
select xmlserialize(document
xmlelement("root",
xmlagg(
xmlelement("emp"
, xmlforest(
t.key as "ID"
, t.name as "ename"
, xmlagg(
xmlforest(d.description as "Desc")
order by d.description -- if necessary
) as "Descriptions"
) as clob indent
from test_table t
left outer join test_desc d on d.key = t.key
group by t.key
, t.name
;Edited by: odie_63 on 11 juil. 2012 14:54 - added 2nd option -
Analytic Functions with GROUP-BY Clause?
I'm just getting acquainted with analytical functions. I like them. I'm having a problem, though. I want to sum up the results, but either I'm running into a limitation or I'm writing the SQL wrong. Any hints for me?
Hypothetical Table SALES consisting of a DAY_ID, PRODUCT_ID, PURCHASER_ID, PURCHASE_PRICE lists all the
Hypothetical Business Question: Product prices can fluctuate over the course of a day. I want to know how much per day I would have made had I sold one each of all my products at their max price for that day. Silly question, I know, but it's the best I could come up with to show the problem.
INSERT INTO SALES VALUES(1,1,1,1.0);
INSERT INTO SALES VALUES(1,1,1,2.0);
INSERT INTO SALES VALUES(1,2,1,3.0);
INSERT INTO SALES VALUES(1,2,1,4.0);
INSERT INTO SALES VALUES(2,1,1,5.0);
INSERT INTO SALES VALUES(2,1,1,6.0);
INSERT INTO SALES VALUES(2,2,1,7.0);
INSERT INTO SALES VALUES(2,2,1,8.0);
COMMIT;
Day 1: Iif I had sold one product 1 at $2 and one product 2 at $4, I would have made 6$.
Day 2: Iif I had sold one product 1 at $6 and one product 2 at $8, I would have made 14$.
The desired result set is:
DAY_ID MY_MEASURE
1 6
1 14The following SQL gets me tantalizingly close:
SELECT DAY_ID,
MAX(PURCHASE_PRICE)
KEEP(DENSE_RANK FIRST ORDER BY PURCHASE_PRICE DESC)
OVER(PARTITION BY DAY_ID, PRODUCT_ID) AS MY_MEASURE
FROM SALES
ORDER BY DAY_ID
DAY_ID MY_MEASURE
1 2
1 2
1 4
1 4
2 6
2 6
2 8
2 8But as you can see, my result set is "longer" than I wanted it to be. I want a single row per DAY_ID. I understand what the analytical functions are doing here, and I acknowledge that I am "not doing it right." I just can't seem to figure out how to make it work.
Trying to do a sum() of max() simply does not work, nor does any semblance of a group-by clause that I can come up with. Unfortunately, as soon as I add the windowing function, I am no longer allowed to use group-by expressions (I think).
I am using a reporting tool, so unfortunately using things like inline views are not an option. I need to be able to define "MY_MEASURE" as something the query tool can apply the SUM() function to in its generated SQL.
(Note: The actual problem is slightly less easy to conceptualize, but solving this conundrum will take me much closer to solving the other.)
I humbly solicit your collective wisdom, oh forum.Thanks, SY. I went that way originally too. Unfortunately that's no different from what I could get without the RANK function.
SELECT DAY_ID,
PRODUCT_ID,
MAX(PURCHASE_PRICE) MAX_PRICE
FROM SALES
GROUP BY DAY_ID,
PRODUCT_ID
ORDER BY DAY_ID,
PRODUCT_ID
DAY_ID PRODUCT_ID MAX_PRICE
1 1 2
1 2 4
2 1 6
2 2 8 -
Using aggregrate functions without group by
Hi
I have a query which is
select empno,deptno,count(*) from emp group by empno,deptno;
Is there any thing which will help me to return empno,deptno without using group by clause?
Appreciate your help on the above?
Thanks & Regards
Thakur Manoj RThis will give the same result:
select empno, deptno, count(*) over (partition by empno, deptno) from emp;If you want to see the number of employees in the same department you could use:
select empno, deptno, count(*) over (partition by deptno) from emp;But what is your intention? What is wrong about "group by"?
Edited by: hm on 27.01.2011 00:10 -
-- SQL -- GROUP BY clause: non-aggregate fields mandate
Hello,
I was studying Databases, (particularly the retrieval of the data), and found something interesting.
While using an Aggregate Function in the SELECT clause, it is mandatory to have all the non-aggregate fields in the SELECT clause to be there in the GROUP BY clause.
For example,
SELECT dept_no, SUM(salary)
FROM employee
GROUP BY dept_no;
The above SQL works fine.
But, what if the user misses the dept_no in the GROUP BY clause or he/she misses the GROUP BY clause itself?
Certainly, it is an error.
Why is this error not handled by the database. I mean, the database should be smart/intelligent enough to add the GROUP BY clause by itself. So suppose, if I miss out the GROUP BY clause or miss a non-aggregate field from the SELECT clause when I am having at least one aggregate function on a field with at least one non-aggregated field in the SELECT clause, the database should check the GROUP BY clause at time of compilation and add the mandate missed out fields in the GROUP BY clause.
Example,
SQL1:_
SELECT dept_no, SUM(salary)
FROM employee
GROUP BY dept_no;
SQL2:_
SELECT dept_no, SUM(salary)
FROM employee;
Here, the SQL1 and SQL2, both should give me same outputs without an error.
I am unable to understand why is this not handled?Hi,
998478 wrote:
... If we mix aggregate and non-aggregate values then there must be a GROUP BY clause containing all the non-aggregate values. Why is this not handled by the database/compiler itself? It IS handled by the compiler itself. The compiler handles it by raising an error. The compiler has no way of knowing whether you want to remove something from the SELECT clause, or to add something to the GROUP BY clause, or not to use aggregate functions, or to use more aggregate functions, or some combination of the above. If the compiler re-wrote your code, and did any of these things automatically, it would be wrong more often than it was right, and you would (rightly) be complaining about its behavior.
For example, this is clearly wrong:
SELECT deptno
, job
, SUM (sal)
FROM scott.emp
GROUP BY deptno
;What is the right way to fix it?
<h3>1. Remove something from the SELECT clause</h3>
SELECT deptno
, SUM (sal)
FROM scott.emp
GROUP BY deptno
;<h3>2. Add something to the GROUP BY clause</h3>
SELECT deptno
, job
, SUM (sal)
FROM scott.emp
GROUP BY deptno
, job
;<h3>3. Not use aggregate functions</h3>
SELECT deptno
, job
, sal
FROM scott.emp
;<h3>4. Use more aggregate functions</h3>
SELECT deptno
, MIN (job)
, SUM (sal)
FROM scott.emp
GROUP BY deptno
;These aren't all the options, either. For example, the correct fix might be to use analytic functions instead of aggregate functions.
How can anybody say which of these is right? All of them are the right answer for some problem.
By the way, saying that everying in the SELECT clause must be an aggregate or in the GROUP BY clause is a bit over-simplified.
More completely, here are the ABC's of GROUP BY:
When you use a GROUP BY clause and/or an aggregate function, then everything in the SELECT clause must be:
(A) an <b>A</b>ggregate function,
(B) one of the "group <b>B</b>y" expressions,
(C) a <b>C</b>onstant, or
(D) something that <b>D</b>epends entirely on the above. (For example, if you "GROUP BY TRUNC(dt)", you can SELECT "TO_CHAR (TRUNC(dt), 'Mon-DD')").
Edited by: Frank Kulash on Apr 13, 2013 1:44 PM
Added code examples. -
Why doesn't PIVOT clause work with COLLECT aggregate function in 11g ?
Hello all !
I am really puzzled as to what is considered an aggregate function in the context of the PIVOT clause in 11g.
I have been toying with quite a few things related to collections lately and this arose as an aside :
CREATE TABLE TEST_COLL
NODE_ID VARCHAR2(15 CHAR) NOT NULL,
NODE_VALUE VARCHAR2(45 CHAR) NOT NULL,
NODE_LEVEL NUMBER(1) NOT NULL
CREATE OR REPLACE TYPE TREE_NODE AS OBJECT
NODE_KEY VARCHAR2( 15 CHAR),
NODE_NAME VARCHAR2(127 CHAR)
CREATE OR REPLACE TYPE TREE_NODES AS TABLE OF TREE_NODE NOT NULL;At this stage I am sure we all agree that the query
SELECT NODE_LEVEL,
CAST(COLLECT(TREE_NODE(NODE_ID, NODE_VALUE)) AS TREE_NODES) AS NODES
FROM TEST_COLL
GROUP BY NODE_LEVEL;is perfectly valid as the COLLECT function is an aggregate function according to the [Official Documentation|http://docs.oracle.com/cd/E11882_01/server.112/e10592/functions031.htm#i1271564]
But then, one of the following two queries should work
SELECT CAST(REGION_NODES AS TREE_NODES) AS REGIONS,
CAST(DEPARTMENT_NODES AS TREE_NODES) AS DEPARTMENTS,
CAST(AREA_NODES AS TREE_NODES) AS AREAS,
CAST(CENTRE_NODES AS TREE_NODES) AS CENTRES
FROM (SELECT NODE_LEVEL, TREE_NODE(NODE_ID, NODE_VALUE) AS NODE
FROM TREE_COLL
PIVOT (COLLECT(NODE) FOR NODE_LEVEL IN (1 AS REGION_NODES,
2 AS DEPARTMENT_NODES,
3 AS AREA_NODES,
4 AS CENTRE_NODES
or (better)
SELECT REGION_NODES AS REGIONS,
DEPARTMENT_NODES AS DEPARTMENTS,
AREA_NODES AS AREAS,
CENTRE_NODES AS CENTRES
FROM (SELECT NODE_LEVEL, TREE_NODE(NODE_ID, NODE_VALUE) AS NODE
FROM TREE_COLL
PIVOT (CAST(COLLECT(NODE) AS TREE_NODES) FOR NODE_LEVEL IN (1 AS REGION_NODES,
2 AS DEPARTMENT_NODES,
3 AS AREA_NODES,
4 AS CENTRE_NODES
);yet, both fail with
ORA-56902: expect aggregate function inside pivot operationInvestigating further, I found the same behaviour when using XMLAGG as the aggregate function in the PIVOT clause.
Is this normal ? And if it is, is there any other way to achieve the result I was anticipating ?
My version is
SQL> SELECT BANNER FROM V$VERSION;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE 11.2.0.3.0 Production
TNS for 64-bit Windows: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - ProductionThanks in advance
Best Regards
PhilipMost likely a bug. But you can bypass it by using any other aggregate making sure group consists of a single row and apply collect to a pivoted value. Yes, the cost is double aggregation. And also there is another cost - you would need to create MAP member function otherwise aggreations like MAX/MIN, etc. will not work:
CREATE OR REPLACE TYPE TREE_NODE AS OBJECT
NODE_KEY VARCHAR2( 15 CHAR),
NODE_NAME VARCHAR2(127 CHAR),
map member function f return varchar2
Type created.
CREATE OR REPLACE TYPE BODY TREE_NODE AS
map member function f return varchar2 is
begin
return NODE_NAME;
end f;
end;
Type body created.
CREATE OR REPLACE TYPE TREE_NODES AS TABLE OF TREE_NODE NOT NULL
Type created.
SQL> select *
2 from test_coll
3 /
NODE_ID NODE_VALUE NODE_LEVEL
1 A 1
2 B 2
3 C 3
4 D 4
5 E 1
6 F 2
7 G 3
8 H 4
8 rows selected.
SQL> Now:
SELECT CAST(COLLECT(REGION_NODES) AS TREE_NODES) AS REGIONS,
CAST(COLLECT(DEPARTMENT_NODES) AS TREE_NODES) AS DEPARTMENTS,
CAST(COLLECT(AREA_NODES) AS TREE_NODES) AS AREAS,
CAST(COLLECT(CENTRE_NODES) AS TREE_NODES) AS CENTRES
FROM (
SELECT ROWID RID,
NODE_LEVEL,
TREE_NODE(NODE_ID, NODE_VALUE) AS NODE
FROM TEST_COLL
PIVOT (MAX(NODE) FOR NODE_LEVEL IN (
1 AS REGION_NODES,
2 AS DEPARTMENT_NODES,
3 AS AREA_NODES,
4 AS CENTRE_NODES
REGIONS(NODE_KEY, NODE_NAME) DEPARTMENTS(NODE_KEY, NODE_NAME) AREAS(NODE_KEY, NODE_NAME) CENTRES(NODE_KEY, NODE_NAME)
TREE_NODES(TREE_NODE('1', 'A'), TREE_NODE('5', 'E')) TREE_NODES(TREE_NODE('6', 'F'), TREE_NODE('2', 'B')) TREE_NODES(TREE_NODE('7', 'G'), TREE_NODE('3', 'C')) TREE_NODES(TREE_NODE('8', 'H'), TREE_NODE('4', 'D'))
SQL> SY. -
Custom aggregate function inside a package.
Hi there,
I'm trying to write a custom aggregate function and group that function inside a package together with some other functions that I have. As an example (to simulate the problem I have) suppose my custom aggregation to do a summation of numbers looks like:
CREATE OR REPLACE TYPE SUM_AGGREGATOR_TYPE AS OBJECT (
summation NUMBER,
STATIC FUNCTION ODCIAggregateInitialize(agg_context IN OUT
SUM_AGGREGATOR_TYPE) RETURN NUMBER,
MEMBER FUNCTION ODCIAggregateIterate(self IN OUT SUM_AGGREGATOR_TYPE,
next_number IN NUMBER) RETURN NUMBER,
MEMBER FUNCTION ODCIAggregateMerge(self IN OUT SUM_AGGREGATOR_TYPE,
para_context IN SUM_AGGREGATOR_TYPE) RETURN NUMBER,
MEMBER FUNCTION ODCIAggregateTerminate(self IN SUM_AGGREGATOR_TYPE,
return_value OUT NUMBER, flags IN NUMBER) RETURN NUMBER
CREATE OR REPLACE TYPE BODY SUM_AGGREGATOR_TYPE IS
STATIC FUNCTION ODCIAggregateInitialize(agg_context IN OUT
SUM_AGGREGATOR_TYPE)
RETURN NUMBER IS
BEGIN
agg_context := SUM_AGGREGATOR_TYPE(NULL);
RETURN ODCIConst.Success;
END;
MEMBER FUNCTION ODCIAggregateIterate(self IN OUT SUM_AGGREGATOR_TYPE,
next_number IN NUMBER)
RETURN NUMBER IS
BEGIN
IF self.summation IS NULL THEN
self.summation := next_number;
ELSIF summation IS NOT NULL THEN
self.summation := self.summation + next_number;
END IF;
RETURN ODCIConst.Success;
END;
MEMBER FUNCTION ODCIAggregateMerge(self IN OUT SUM_AGGREGATOR_TYPE,
para_context IN SUM_AGGREGATOR_TYPE)
RETURN NUMBER IS
BEGIN
self.summation := self.summation + para_context.summation;
RETURN ODCIConst.Success;
END;
MEMBER FUNCTION ODCIAggregateTerminate(self IN SUM_AGGREGATOR_TYPE,
return_value OUT NUMBER, flags IN NUMBER)
RETURN NUMBER IS
BEGIN
return_value := self.summation;
return ODCIConst.Success;
END;
END;
If I write the following function definition:
CREATE OR REPLACE FUNCTION MY_SUM(input NUMBER)
RETURN NUMBER PARALLEL_ENABLE AGGREGATE USING SUM_AGGREGATOR_TYPE;
and corresponding type declaration to test:
CREATE OR REPLACE TYPE VECTOR
IS
TABLE OF NUMBER;
this statement:
select my_sum(column_value) from table(vector(1, 2, 1, 45, 22, -1));
gives the correct result of 70. However, creating a package with the function definition:
CREATE OR REPLACE PACKAGE MY_FUNCTIONS AS
FUNCTION MY_SUM(input NUMBER)
RETURN NUMBER PARALLEL_ENABLE AGGREGATE USING SUM_AGGREGATOR_TYPE;
END;
and calling it via:
select MY_FUNCTIONS.my_sum(column_value) from table(vector(1, 2, 1, 45, 22, -1));
explodes with:
ORA-00600: internal error code, arguments: [17090], [], [], [], [], [], [], [], [], [], [], []
Is it possible to have custom aggregate functions nested inside package declarations?
I'm using Oracle 11g, Release 2 (11.2.0.1.0).HiddenName wrote:
Is it possible to have custom aggregate functions nested inside package declarations?Yes, it is possible, you have succesfuly created your function. Your problem is that the database throws ORA-600 on execute. And with ORA-600 you can do 2 things: 1) google ORA-600 17090 or 2) contact your Oracle Support.
You could also try to declare the function without PARALLEL_ENABLE - just to try to see if it changes anything. You can also try to call your function against a regular table with rows and columns - not against an collection type with table() operator.
Anyway - these 2 tests should be usefull for Oracle Support.
I never tried to put a custom aggregate function into a package. First - the cases when you need a custom aggregate function to be written for your system are very rare. Second - even if I needed 1 then I never needed 2 or more custom aggregate functions on my system. And as I do not like to make my life more complex than necessary, I have created it as a stand-alone function. And it is works (slowly).I tried using a standard table as you suggested:
CREATE TABLE TEST_DATA
test_value NUMBER
INSERT INTO TEST_DATA
(SELECT column_value test_value from TABLE(vector(1, 2, 1, 45, 22, -1)));
COMMIT;
select my_sum(test_value) from test_data;
select my_functions.my_sum(test_value) from test_data;
I also tried removing the PARALLEL_ENABLE clause to create the package as follows:
CREATE OR REPLACE PACKAGE MY_FUNCTIONS AS
FUNCTION MY_SUM(input NUMBER)
RETURN NUMBER AGGREGATE USING SUM_AGGREGATOR_TYPE;
END;
And unfortunately it still breaks with the following error: SQL Error: ORA-00600: internal error code, arguments: [17090]. This looks like an Oracle bug to me as the PL/SQL parsing engine should have disallowed me to even create this if it is not supported in Oracle. Instead, it allows me to create the package, and breaks when I call the function with this weird error (additionally cutting my connection from the database) instead of disallowing me to do this altogether and printing a nice error message telling me that Oracle doesn't support this. How would I go about logging a ticket for this?
Edited by: wcmatthysen on Dec 1, 2010 12:51 PM -
Analytic function and aggregate function
What are analytic function and aggregate function. What is difference between them?
hi,
Analytic Functions :----------
Analytic functions compute an aggregate value based on a group of rows. They differ from aggregate functions in that they return multiple rows for each group. The group of rows is called a window and is defined by the analytic_clause. For each row, a sliding window of rows is defined. The window determines the range of rows used to perform the calculations for the current row. Window sizes can be based on either a physical number of rows or a logical interval such as time.
Analytic functions are the last set of operations performed in a query except for the final ORDER BY clause. All joins and all WHERE, GROUP BY, and HAVING clauses are completed before the analytic functions are processed. Therefore, analytic functions can appear only in the select list or ORDER BY clause.
Analytic functions are commonly used to compute cumulative, moving, centered, and reporting aggregates.
Aggregate Functions :----------
Aggregate functions return a single result row based on groups of rows, rather than on single rows. Aggregate functions can appear in select lists and in ORDER BY and HAVING clauses. They are commonly used with the GROUP BY clause in a SELECT statement, where Oracle Database divides the rows of a queried table or view into groups. In a query containing a GROUP BY clause, the elements of the select list can be aggregate functions, GROUP BY expressions, constants, or expressions involving one of these. Oracle applies the aggregate functions to each group of rows and returns a single result row for each group.
If you omit the GROUP BY clause, then Oracle applies aggregate functions in the select list to all the rows in the queried table or view. You use aggregate functions in the HAVING clause to eliminate groups from the output based on the results of the aggregate functions, rather than on the values of the individual rows of the queried table or view.
let me know if you are feeling any problem in understanding.
thanks.
Edited by: varun4dba on Jan 27, 2011 3:32 PM -
Group by clause using query builder
Hi,
I have some event pages (pages created using a template called event) which are tagged with event types and I have 5 event types in total. In the event listing page, i want to show the events grouped by event types.
Is there a facility in query builder to use "group by" which returns be results in different buckets?
Is thats not the case, i have to run 1 query per event type which means i have to run 5 queries. (or i get the event type as facets -> get the buckets -> get the predicate for each bucket -> run one query per bucket which again is nothing buket one query per event type). I dont want to do that.
Hence using the query builder or any other form of querying, is there a way to group the results?
Regards,
yadhuPerfect... thats answers the query...
Basically the summary is I cannot use aggregate functions like group by. Once i get the search results, i can either use facets, get the bucket predicates and drill down the search OR get all the results, do look up on property (using Node.getProperty) of each node in the result and build my UI based on mere coding. Am I right? -
Aggregate functions in EJBQL ???
Does the latest version of Oracle App server support aggregate functions like SUM/COUNT/AVG in the EJBQL?
Does the latest version of Oracle App server support aggregate functions like SUM/COUNT/AVG in the EJBQL? Hi Swami --
The latest version of Oracle9iAS - v903 is J2EE 1.3 compatible so it supports all of the EJB 2.0 specification.
The EJB 2.0 specification lists the following functions for EJBQL:
String Functions:
CONCAT(String, String) returns a String
SUBSTRING(String, start, length) returns a String
LOCATE(String, String [, start]) returns an int
LENGTH(String) returns an int
Arithmetic Functions:
ABS(number) returns a number (int, float, or double)
SQRT(double) returns a double
The latest version of the EJB 2.1 specification which will be part of J2EE 1.4, has added support for aggregate functions like orderby, sum, count, etc.
11.2.7.2 Aggregate Functions in the SELECT Clause
The result of an EJB QL query may be the result of an aggregate function applied to a path expression.
The following aggregate functions can be used in the SELECT clause of an EJB QL query: AVG,
COUNT, MAX, MIN, SUM.
We will support these when the EJB 2.1 specification is finalized and we produce our J2EE 1.4 compatible implementation.
cheers
-steve- -
SQL Server Compact 3.5 GROUP BY Clause Problem
Hi,
I have a table as below:
Tag(string) Name(string) Description(string) LocationID(Guid)
"SELECT Tag, Name, Description, LocationID FROM MyTable GROUP BY LocationID"
gives me an error, any ideas on what I am doing wrong?
Thanks
Paul.
Paul WainwrightHi pr_wainwright,
GROUP BY statement is used in conjunction with the aggregate functions to group the result-set by one or more columns
e.g
select Tag,name, Description, sum(locationid) from mytable group by
Tag,name, Description
SELECT columnname, aggregatefunction(columnname)
FROM tablename
WHERE columnname operator value
GROUP BY columnname; -
How to write a SQL Query without using group by clause
Hi,
Can anyone help me to find out if there is a approach to build a SQL Query without using group by clause.
Please site an example if is it so,
RegardsI hope this example could illuminate danepc on is problem.
CREATE or replace TYPE MY_ARRAY AS TABLE OF INTEGER
CREATE OR REPLACE FUNCTION GET_ARR return my_array
as
arr my_array;
begin
arr := my_array();
for i in 1..10 loop
arr.extend;
arr(i) := i mod 7;
end loop;
return arr;
end;
select column_value
from table(get_arr)
order by column_value;
select column_value,count(*) occurences
from table(get_arr)
group by column_value
order by column_value;And the output should be something like this:
SQL> CREATE or replace TYPE MY_ARRAY AS TABLE OF INTEGER
2 /
Tipo creato.
SQL>
SQL> CREATE OR REPLACE FUNCTION GET_ARR return my_array
2 as
3 arr my_array;
4 begin
5 arr := my_array();
6 for i in 1..10 loop
7 arr.extend;
8 arr(i) := i mod 7;
9 end loop;
10 return arr;
11 end;
12 /
Funzione creata.
SQL>
SQL>
SQL> select column_value
2 from table(get_arr)
3 order by column_value;
COLUMN_VALUE
0
1
1
2
2
3
3
4
5
6
Selezionate 10 righe.
SQL>
SQL> select column_value,count(*) occurences
2 from table(get_arr)
3 group by column_value
4 order by column_value;
COLUMN_VALUE OCCURENCES
0 1
1 2
2 2
3 2
4 1
5 1
6 1
Selezionate 7 righe.
SQL> Bye Alessandro -
Aggregate functions, %notfound and group by
Hi,
Below are 2 versions of a script that query the employees table and get the max salary by specific departments. Department ids are held in a varray.
With 'group by':
declare
type c is ref cursor;
c1 c;
sal employees.salary%type;
type rid is varray(3) of number;
r_id rid:=rid();
begin
r_id.extend(3);
r_id(1):=50;
r_id(2):=80;
r_id(3):=200;
for y in 1..3
loop
open c1 for select max(salary) from employees
where department_id =r_id(y)
group by department_id;
fetch c1 into sal;
if c1%notfound then
dbms_output.put_line('not found');
else
dbms_output.put_line(sal);
end if;
close c1;
end loop;
end;No 'group by':
declare
type c is ref cursor;
c1 c;
sal employees.salary%type;
type rid is varray(3) of number;
r_id rid:=rid();
begin
r_id.extend(3);
r_id(1):=50;
r_id(2):=80;
r_id(3):=200;
for y in 1..3
loop
open c1 for select max(salary) from employees
where department_id =r_id(y);
fetch c1 into sal;
if c1%notfound then
dbms_output.put_line('not found');
else
dbms_output.put_line(sal);
end if;
close c1;
end loop;
end;The version with no group by clause always returns false for cursor attribute %notfound. Whereas in the version with the clause %notfound is true when an non-existent department id is entered. Why is this?
Product info: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0
PL/SQL Release 10.2.0.1.0
Thanks.<strike>Because the group by works on the rows that are returned from the where clause, and then the columns are applied. If you pass a condition into the where clause that causes no rows to be returned, then there's nothing to group by,
Whereas when you select an aggregate query without a group by, you always get a row returned.
eg: select count(*) from (
select max(dummy)
from dual
where dummy = 'Y')
COUNT(*)
1
select count(*) from (
select max(dummy)
from dual
where dummy = 'Y'
group by dummy)
COUNT(*)
0</strike>
Edited by: Boneist on 19-Aug-2009 15:21
Hmm... the documention seems to indicate that you should always get a row back, even if it's null.
I have no idea why adding the group by causes that statement to not be true, then, unless I'm misunderstanding the documentation!!
Maybe you are looking for
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