.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Register
 
Win Surprise Gifts!!!
Congratulations!!!


Top 5 Contributors of the Month
MarieAdela
Imran Ghani
Post New Web Links

Top N PERCENT function analogue using ranking functions

Posted By:      Posted Date: December 04, 2010    Points: 0   Category :Sql Server
 

Hi everybody,

I'm wondering if there is a good way to simulate TOP N PERCENT using RANKING functions? NTILE() comes close, but it doesn't simulate it exactly. It almost looks like we need a new PERCENTILE() ranking function.

Thoughts, ideas?

Thanks in advance.

 

 


Premature optimization is the root of all evil in programming. (c) by Donald Knuth

Naomi Nosonovsky, Sr. Programmer-Analyst

My blog


View Complete Post


More Related Resource Links

can the query be written using RANKING functions

  

I am of the opinion that the query below can be written using a windowing function instead of the self join.

Can anyone help with this please.

 

SELECT 
PersonURN,
AddressURN,
DealerID,
QuoteAmount
FROm #hold a 
where TransactionDate = (SELECT MAX(TransactionDate) FROM #hold b where b.PersonURN = a.PersonURN and b.DealerID = a.DealerID)


Re-writing query using RANKING functions

  

I have the query below and I am trying to use historical queries to retrieve the information, I have put something together but running the Original query and my new query does not bring back thesame results, but i think I may be doing something incorrectly.

 



Working with Ranking Window Functions

  
As the name suggests, ranking functions let you rank the rows in your result set based on specified values in those rows. SQL Server supports four ranking functions:

ROW_NUMBER: Assigns a sequential number to each row in the result set.
RANK: Ranks each row in the result set. If values in the ranking column are the same, they receive the same rank. However, the next number in the ranking sequence is skipped.
DENSE_RANK: Ranks each row in the result set. If values in the ranking column are the same, they receive the same rank. The next number in the ranking sequence is then used to rank the row or rows that follow.
NTILE: Divides the result set into the number of groups specified as an argument to the function. A group number is then assigned to each row identifying which group the row belongs to.

Insert value using Table Value Functions

  
a real gem in Sql Server 2008. mostly people still using Stored procedure may be they shifted to SQL Server but they are not using TVF right now.

Introduction to Functions

  
A function is a section of code that is used to perform an isolated assignment. Once it has performed its assignment, the function can be accessed to present its result(s).

In Transact-SQL, a function is considered an object. After creating the function object, it becomes part of a database. You can then execute it when necessary.

Built-In Functions Fundamentals

  
While your primary job as a database developer consists of creating lists, probably your second most important job is to assist your users with the various assignments they must perform on your application. One way you can assist is to use functions that perform otherwise complex tasks. We introduced and described functions in the previous lesson. To assist your development with the different tasks of a database, Transact-SQL ships with various already created and tested functions. You just need to be aware of these functions, their syntax, and the results they produce.

Built-in Functions - Text and Image Functions in SQL Server

  
Text and image functions operate on TEXT, NTEXT and IMAGE data types. These data types are deprecated with SQL Server 2005 and should be replaced by VARCHAR(MAX), NVARCHAR(MAX) and VARBINARY(MAX) when possible. Alternatively you can also consider storing large string values using XML data type. Text and image functions are nondeterministic.

Future versions of SQL Server will not support TEXT, NTEXT and IMAGE data types. Columns with TEXT / NTEXT data type do not support commonly used string functions such as LEN, LEFT, RIGHT, etc. Furthermore, due to the large size of TEXT data you''re likely to see performance issues if you store such data in the database. However, at times you can''t help but use the TEXT / NTEXT / IMAGE data types (for example when supporting 3rd party databases when you cannot change the schema) - this is when text and image functions come in handy.

Date and Time Functions in SQLSERVER

  
Date and time functions allow you to manipulate columns and variables with DATETIME and SMALLDATETIME data types.

1 DATEPART Function
2 DATENAME Function
3 DAY, MONTH, and YEAR Functions
4 GETDATE and GETUTCDATE Functions
5 DATEADD Functions
6 DATEDIFF Function
7 More SQL Server Functions

Built-in Functions - Aggregate Functions

  
Aggregate functions return a single value summarizing a given data set. All aggregate functions are deterministic. NOTE: AVG, SUM, STDEV, STDEVP, VAR and VARP functions cannot operate on BIT data types; they can operate on all other numeric data types.

Built-in Functions - Date and Time Functions

  
Date and time functions allow you to manipulate columns and variables with DATETIME and SMALLDATETIME data types.

Cursor Functions

  
A cursor allows looping through a record set and performing a certain operation on each record within the set. SQL Server supports three functions that can help you while working with cursors: @@FETCH_STATUS, @@CURSOR_ROWS and CURSOR_STATUS. Cursor functions are non-deterministic.

Built-in Functions - String Functions

  
String functions let you extract various portions of character strings, change the case of strings, concatenate and reverse strings and perform many other types of manipulations. All built-in string functions are deterministic with the exception of CHARINDEX and PATINDEX

Built-in Functions - Text and Image Functions

  
Text and image functions operate on TEXT, NTEXT and IMAGE data types. These data types are deprecated with SQL Server 2005 and should be replaced by VARCHAR(MAX), NVARCHAR(MAX) and VARBINARY(MAX) when possible. Alternatively you can also consider storing large string values using XML data type. Text and image functions are nondeterministic.

User Defined Functions in Microsoft SQL Server

  
User Defined Functions are compact pieces of Transact SQL code, which can accept parameters, and return either a value, or a table. They are saved as individual work units, and are created using standard SQL commands. Data transformation and reference value retrieval are common uses for functions. LEFT, the built in function for getting the left part of a string, and GETDATE, used for obtaining the current date and time, are two examples of function use. User Defined Functions enable the developer or DBA to create functions of their own, and save them inside SQL Server.

Essential SQL Server Date, Time and DateTime Functions

  
The essential date and time functions that every SQL Server database should have to ensure that you can easily manipulate dates and times without the need for any formatting considerations at all.

Date and Time Data Types and Functions

  
The following sections in this topic provide an overview of all Transact-SQL date and time data types and functions. For information and examples that are common to date and time data types and functions

Content page control passes as argument to javascript function

  

Here is the content page:

********************************************************************

<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="JavaDynamicCopyValue.aspx.cs" Inherits="JavaDynamicCopyValue" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
 <script type="text/javascript" >
 function copyValue(input, output )
{
   ouput.value = input.value;
   return true;
}
 </script>
 <asp:TextBox ID="txt1" runat="server" onchange="copyValue(this,document.getElementById('<%=txt2.ClientID%>'))"></asp:TextBox>
    <br />
    <br />
    <asp:TextBox ID="txt2" runat="server"></asp:TextBox>
</asp:Content>

********************************************************************

I got a javascript run time error says output is undefined. if I view source of the page, the txt1 markup became:

<input name="ctl00$ContentPlaceHol

Categories: 
ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend