Oracle provides a number of powerful analytic functions that can be used to accomplish requirements that may require a stored procedure to be implemented.The analytic function calculates the aggregated values based on a set of data rows, which are different from the aggregate functions, and they return multiple rows of
Today, a co-worker called me and asked me about this problem that was listed in my daily development, and it's true that both of them are related to grouping, but note that one is a grouping function and the other is an analytic function, The table used to explain the example of Scott's EMP and dept tables in Oracle's schema:
Mister Orders said: Need to count the number of each department in the company and each department of wages issued by the sum;
Suppose there is a table studentName Score Inserttime (name: Name score: Score inserttime: Test time)Zhang 320 2015-08-08Lee 412 2015-09-01Little Q 33 2015-09-03Zhang 320 2015-09-08Lee 412 2015-07-01Little Q 25 2015-06-03Now ask everyone to sort by the order of the test time, write out the Oracle statementFor:Select Row_number () over (partition by name order by Inserttime) row_number,student.* from studentExplain:Partition by first grouping by name, order by in order by InserttiomResultsZhang 3
Label:Recognize analytic functionsWhat is an analytic function?Analytic functions are powerful functions that Oracle specifically uses to address the statistical requirements of complex reports, which can be grouped in data and then calculated based on some statistical value
Label:SELECT b.*,RANK () over (PARTITION by B.dname ORDER by B.sal) as Rank_num,Dense_rank () over (PARTITION by B.dname ORDER by B.sal) as Dence_rank,MIN (SAL) KEEP (Dense_rank first ORDER by B.sal) through (PARTITION by B.dname) as First_val,MAX (SAL) KEEP (Dense_rank last ORDER by B.sal) through (PARTITION by B.dname) as Last_val,LAG (Sal, 1, 0) over (PARTITION by B.dname ORDER by B.sal) as Pre_val,Leads (SAL, 1, 0) over (PARTITION by B.dname ORDER by B.sal) as Following_val,First_value (B.sa
Tags: value aggregation function numeric type different implicit strong execution windowOracle provides a number of powerful analytic functions that can be used to accomplish requirements that may require a stored procedure to be implemented. The analytic function calculates the aggregated values based on a set of data rows, which are different from the aggregate
there anything like from the first row after n to the current row, from the current row to the last row in the group N rows?Oh, that is not, right, you are not enough brains, remember so many???It's over, but there's a window that starts at the current line and ends at the current line, but it's pointless, what do you want to do? So, count, at least 9.Considering the rows and range two, there are 18 more of them. Plus the first 6, that's 24. But there are 18 more of them, and the odds are less
Common analytic functions:1. First,last--Suppose A: = min (bonus) Keep (Dense_rank First Order by salary)--Assuming that the minimum wage is 1000,a for employees who are equal to 1000 of the wage, take the minimum bonus--Suppose B: = min (bonus) Keep (Dense_rank Last order by salary)--assuming a maximum wage of 9999,b is the minimum bonus for employees who are equal to 9999 of the wage--as an aggregation
Aggregation functions can be performed in either analytic or non-analytic mode. Aggregate functions in non-analytic mode reduce the result set to fewer rows of data. However, in analytic mode, the aggregate function does not reduc
In fact, it's a good way to work with analytic functions, flipping through Tom's book and including one of the examples here. For example, to query the Scott.emp table for user Sal ordering information, you can use the following query: SQL> SELECTDeptno, ename,2Row_number () Over(PARTITION byDeptnoORDER bySalDESC) Seq3 fromEMP; DEPTNO ename SEQ---------- ---------- ---------- TenKING1 Ten
), originally without the analysis function when using the subquery method, but more trouble, ashamed, I use a subquery some still can not find out.The syntax is as follows:Lag (value_expression [, offset] [, default]) over ([query_partition_clase] order_by_clause);Leads (value_expression [, offset] [, default]) over ([query_partition_clase] order_by_clause);whichValue_expression: Can be a field or a built-in function.Offset is a positive integer, which defaults to 1, indicating the number of re
) asNumcomimgwhereRowNumber> + Results: These two methods, is just a list of rewnumber? Of course not, look at the internal differences: On two SQL, add the following SQL, and use MS's "include execution plan" to see execution Details: SET STATISTICS on
GO SQL to execute: SET STATISTICSTime on
GO
Select Top TenNumcomimg.* from
( SelectRow_number () Over(Order byIdASC) asRowNumber* from(Select * from [Tccline].[dbo].[Cline_commonimage]) ascomimg) asNumcomimgwhereRowNumber> +
SET STATI
by sum(Customer_sales)descNULLS last) rank fromUser_orderGroup byregion_id, customer_id)whereRank 3;--min Keep First last find customers with the highest and lowest order total--min can only be used for Dense_rank--the Min function is used to guarantee that a unique record is returned when there are multiple first/last cases, and the error is removed .--the role of Keep. Tells Oracle to keep only records that meet the keep criteria. Select min(customer_id) Keep (Dense_rank firstOrder by sum(
Tags: nbsp Search rank Technology share according to picture Oracl des SeleSuppose there is a student table student, the student table has a name, a score, a course number, and now I need to sort the students ' grades according to the course.SELECT * FROM Student1. Rank over () can be achieved on the student rankings, characterized by the same results as two are tied, as follows 1 2 2 4 5Select Name,CourseRank () Over (partition by course ORDER BY score Desc) as rankfrom student;2. Dense_rank ()
Tags: over select Note Keyword distribution arc moving average aggregate function first articleIntroduction to Oracle Common analytic functions (ranking function + window function)November 30, 2014 ? database 3903 words ? No comments? Read 7,772 times Rating functionThe common rating functions are as follows:
Rank (): Returns the rank of the data item
Tag:wm_concatrowsbetween plus 1 1 ratio function First value last value before 1 1 /* Table of Contents: 1. Syntax 2. Common functions and usages 2.1 sort functions 2.2wm_concat () enables merging of different rows and fields !!!! Production environment with caution 2.3 window usage 2.4 ratio function Ratio_to_report () over (partition by) 2.5 previous lag lead 2.6 first first_value Last Last_value 2.7 p
Oracle's analytic functions are powerful, and work is often used over the years. This time, the usual use of the analysis function to sort out. for future viewing.We take cases to learn, so it is more easy to understand.1. Build a tableCREATE table earnings--Working Money Table ( earnmonth varchar2 (6),--Working month area VARCHAR2 (20),--working areas Sno VARCHAR2 (1 0),---worker number sname
Hive There are a number of analytic functions available to complete the responsible statistical analysis. This article first describes the sum , AVG , MIN , the four functions of Max . Environmental information:Hive version number is Apache-hive-0.14.0-binHadoop version number is hadoop-2.6.0Tez version number is tez-0.7.0To construct the data:p088888888888,2016-
), originally without the analysis function when using the subquery method, but more trouble, ashamed, I use a subquery some still can not find out.The syntax is as follows:Lag (value_expression [, offset] [, default]) over ([query_partition_clase] order_by_clause);Leads (value_expression [, offset] [, default]) over ([query_partition_clase] order_by_clause);whichValue_expression: Can be a field or a built-in function.Offset is a positive integer, which defaults to 1, indicating the number of re
Beginner PL/SQL.In Oracle, the 3 analytic functions of Rank,dense_rank and row_number can be used to number records, and one of the above three methods can be considered in handling record rankings.RANK: Each row is numbered by the condition after order by, and when the comparison field is equal, the two lines have the same number, and the next record jumps.Dense_rank: Sort by rank, records that compare fie
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