db2 aggregate functions

Label:We all know that when a case is applied in SQL, the information in the database is converted For example, select (Case sex if 0 then ' men ' else ' end) as sex from Studentinfo So what does it do in the aggregate function? SELECTSex fromStudentSELECTSexCOUNT(*) asNum fromStudentGROUP bySexSELECTSex,province,COUNT(*) asNum fromStudentGROUP bysex,provinceSELECTSex,province,COUNT(province) asNum fromStudentGROUP bysex,provinceSELECTSex,provin

aggregation. // // public SqlString Terminate () { string output = string. Empty; //delete The trailing comma, if any if (this.intermediateresult! = NULL this.intermediateResult.Length > 0) { output = this.intermediateResult.ToString (0, This.intermediateResult.Length); } return new SqlString (output);}public void Read (BinaryReader R){Intermediateresult = new StringBuilder (r.readstring ());}public void Write (BinaryWriter W){W.write (This.intermediateResult.ToString ());}}H

aggregation. // // public SqlString Terminate () { string output = string. Empty; //delete The trailing comma, if any if (this.intermediateresult! = NULL this.intermediateResult.Length > 0) { output = this.intermediateResult.ToString (0, This.intermediateResult.Length); } return new SqlString (output);}public void Read (BinaryReader R){Intermediateresult = new StringBuilder (r.readstring ());}public void Write (BinaryWriter W){W.write (This.intermediateResult.ToString ());}}H

This is a very interesting question. It makes sense to think carefully. We know that clustering functions are also called column functions. They are calculated based on the entire column of data, while the WHERE clause filters data rows, in the screening process, relying on "computing results obtained based on filtered data" is a paradox, which is not feasible. To put it more simply, because the clustering

country1. Create a TypeCreate or replace type Strcat_type as Object (cat_string varchar2 (4000),static function Odciaggregateinitialize (Cs_ctx in Out Strcat_type) return number,member function odciaggregateiterate (self on Out strcat_type,value in VARCHAR2) returnNumbermember function Odciaggregatemerge (self in Out strcat_type,ctx2 on out Strcat_type)return number,member function odciaggregateterminate (self on out strcat_type,returnvalue outVarchar2,flags in number) return number);2. Create

Aggregate functions count, max, min, avg, sum...Select count (*) from T_EmployeeSelect Max (FSalary) from T_EmployeeSort ASC ascending DESC descendingSelect * from T_Employee order by FageSort by age in descending order. Sort by salary in ascending order if the age is the sameSelect * from T_Employee order by FAge DESC, FSalary ASCOrder by must be placed after the where clauseWildcard FilterUse like for wil

~ present: UF software 2 1995-01-01~2003-06-29: Microsoft China, 2004-07-01~2009-06-29: Shanda Network The SqlStrConcate.dll code (online Help from SQL Server) is as follows: Using System; Using System.Data; Using Microsoft.SqlServer.Server; Using System.Data.SqlTypes; Using System.IO; Using System.Text;[Serializable] [Sqluserdefinedaggregate (Format.userdefined,//use CLR serialization to serialize the intermediate result Isinvar Ianttonulls = True,//optimizer property Isinvarianttoduplicate

element in S, not an element in TS.symmetric_difference (t) s ^ t symmetric differential operation: elements in S or T, but not s and T are commonThe ElementsS.copy () Copy operation: Returns a (shallow copy) copy of SFor mutable collections onlyS.update (t) s |= T (Union) Modify operation: Add a member of T to the SS.intersection_update (t) s = T intersection modification operation: s includes only members of S and TS.difference_update (t) s-= t Difference modification operation: s includes me

Max ()Min ()Average average ()Total count ()Sum () 1. Entity Bean Public ClassTuzi {Public IntId {Get;Set;}Public IntAge {Get;Set;}Public StringName {Get;Set;}} 2. Object Initiator Static List Inittuziinfo () {list New List { New Tuzi {name = " Tuzi001 " , Age = 10 }, New Tuzi {name = " Tuzi002 " , Age = 24 }, New Tuzi {name = " Tuzi003 " , Age = 33 }, New Tuzi {name = " Tuzi004 " , Age = 47 }, New Tuzi {name = " Tuzi005 " , Age = 59 }, New Tuzi {name = " Tuzi006

)) =0andgrouping (User_code) =1) thenuser_code/*when Grouping (TRUNC (trans_time)) =1 THEN ' Subtotal ' */ ELSE user_codeenduser_code,trunc (Trans_time), SUM (Trans_amount), grouping (user_code), grouping (TRUNC (Trans_time)), grouping (trans_Amount) fromtrade_flowgroupbygroupingsets (User_code,trunc (Trans_time), Trans_amount), (User_code,trunc (trans_time)) Selectdecode (Grouping (Trans_amount), 1, ' Subtotal ', 0,user_ Code) user_code,trunc (Trans_time), SUM (Trans_amount), grouping (User_co

. Next, you need to group the "summary table" obtained above by year and month, and count (Order ID) for order quantity, the sum aggregate function calculates the number of paid orders by summation with conditions. Answer: Select order year, order month, count (Order ID) as order quantity, sum (order sales * iif (whether paid =, 0) as paid order quantity, sum (order sales) as sales from (select list. order ID, order year, order month, order sales, w

Label: CREATE TABLE ' T_grade ' (' ID ' int,' Stuname ' varchar (60),' Course ' varchar (60),' Score ' int);Insert INTO ' t_grade ' (' id ', ' stuname ', ' Course ', ' score ') VALUES (' 1 ', ' Zhang San ', ' language ', ' 91 ');Insert INTO ' t_grade ' (' id ', ' stuname ', ' Course ', ' score ') VALUES (' 2 ', ' Zhang San ', ' math ', ' 90 ');Insert INTO ' t_grade ' (' id ', ' stuname ', ' Course ', ' score ') VALUES (' 3 ', ' Zhang San ', ' English ', ' 87 ');Insert INTO ' t_grade ' (' id ',

Aggregation function: A function that summarizes multirow (row) data into a row according to certain rules, and before summarizing the data, you can group the data by a specific column (Coloumn) and then filter by the criteria given again.A: Count function1 SELECT COUNT (Birthday) from customer2 SELECT COUNT (*) from customer3 SELECT COUNT (1) from customer1 and 2 differences: Using a specific column name as a parameter, the column does not calculate the null value of the column within countBoth

([Partition_by_clause] order_by_clause) Example:SELECT MIN ([UnitsInStock]) from [dbo]. [Product]SELECT [Categoryid],min ([UnitsInStock]) from [dbo].[ Product]group by [CategoryID]6. COUNTReturns the number of items in a group. COUNT is similar to the COUNT_BIG function. The only difference between the two functions is their return value. COUNT always returns the int data type value. Count_big always returns the bigint data type value.Grammar:COUN

See the following table: aggregationtable ID Name 1 Zhao 2 Money 1 Sun 1 Li 2 Week If you want to obtain the aggregation result ID Name 1 Zhao Sun Li 2 Qian Zhou Sum, AVG, Count, count (*), Max, and Min cannot be used. These are the aggregation of values. However, we can solve this problem through user-defined

The aggregate functions are shown in the following table: Function Parameters Function COUNT ([all| Distinct]expression) Calculates the number of non-null values in an expression, which can be used for numeric columns, and to remove duplicate values when using Distice COUNT (*) Calculates all rows, including null rows, and cannot use the DISTINCT

Label:SELECT AA. [User_id],cc.[user_name],dd. Name as DEPNAME,AA. Module_id,aa. Module_name,SUM (case AA. Operate_type when ' 2 ' and then Operatenum END ' as ' addnum ',SUM (case AA. Operate_type when ' 3 ' and then Operatenum END ' as ' editnum ',SUM (case AA. Operate_type when ' 4 ' then operatenum END) as ' Delnum 'From (SELECT A.[user_id],a.module_id,c.module_name,a.operate_type,count (1) as Operatenum from dbo. Sys_user_log as aINNER JOIN dbo. Sys_module as C on a.module_id = c.module_idWH

-01-01t00:00:00z) unless you specify a lower bound time range. Then they go back to the time stamp of the Nether.The same set of execution sum () at the float64 point may produce slightly different results. Influxdb before the function is not applicable, results in those small difference sorting points. Example 2 The calculations are grouped in 5 days, Water_level and SELECT SUM(water_level) FROM h2o_feet WHERE time >= ‘2015-08-18T00:00:00Z‘ AND time Results: -------------- time

SC GROUP by SNO have Count (*) >=2 and min (grade) >=60--8, query the number of students who took 2 courses, the course number and results, the results of the query in descending order by grade.Select Sno,cno,grade from SC where cno=2 order by grade DESC--9, professional names and numbers of professionals with less than 2 professional enquiries.Select Sdept,count (*) as number from student group by Sdept have COUNT (sdept) --10, query the name of female students, professional names, results by

After one weeks, I finally began to write a third article. Get Up!Aggregation functions:The aggregate functions provided in SQL can be used to count, sum, find the most value, and so on.Classification:–count: Number of statistics rows–sum: Gets the aggregate value of a single column–avg: Calculating the average of a column– Max: Calculating the maximum value of a