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Object orientated programming within JavaScript 2010-01-28 07:25:45
How to sort data using ASP.net (C#) and SQL 2005/8 2010-01-18 15:23:14
Quick look at some of the new features added to C# 4.0 2010-01-12 21:52:13
SQL 2008 introduced a nifty feature called Table-Valued Parameters (TVP) into its codebase 2010-01-06 22:58:25
How to page data using ASP.net (C#) and SQL 2005/8 2009-10-19 15:01:45
a post about sql joins 2009-09-20 15:50:57
Creating custom/composite controls that expose events in C# 2009-09-15 12:56:32
Populate a TreeView control in a windows application. 2009-08-27 16:01:03
This one is for the PHP enthusiasts, most of you are hopefully probably aware of this. 2009-08-14 09:21:39
I need guinea pigs ;) 2009-08-04 22:26:04
Creating a WYSIWYG textbox for your website is actually quite simple. 2007-02-01 12:00:00
Move items between two listboxes in ASP.net(C#, VB.NET) and PHP 2008-06-12 17:07:43
Firefox word wrapping issues 2008-06-09 09:51:21
2007-02-22 12:00:00
Often you'll hear the term "strongly typed" which refers to certain constraints being enforced regarding variables 2007-01-28 12:00:00
Source code for the following post can be downloaded here. Paging data is one of those basic things most, if not every developer will have to do from time to time. In the following approach, we're going to use a ListView, DataPager and an ObjectDataSource to achieve this. Equally one can use a DataView and simply use it with an ObjectDataSource - I personally prefer the ListView, simply because I feel its a more flexible control. Lets have a look at the ObjectDataSource first: <asp:ObjectDataSource ID="obsFriends" runat="server" SelectCountMethod="CountFriends" SelectMethod="ViewFriends" TypeName="friends" EnablePaging="true"> </asp:ObjectDataSource> Notice that we'll need a "SelectCountMethod", this method returns a count of the total rows that needs paging, the "SelectMethod" is the method that returns the actual rows. TypeName is the class (along with its namespaces) where the ObjectDataSource can find these methods. That class will look something like the following: using System; using System.Data; using System.Configuration; using System.ComponentModel; using System.Data.SqlClient; [DataObject()] public class friends { [DataObjectMethod(DataObjectMethodType.Select)] public static DataTable ViewFriends(Int32 maximumRows, Int32 startRowIndex) { using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["Default"].ConnectionString)) { using (SqlCommand command = new SqlCommand("ViewFriends", connection)) { command.CommandType = CommandType.StoredProcedure; command.Parameters.AddWithValue("@maximumRows", maximumRows); command.Parameters.AddWithValue("@startRowIndex", startRowIndex); using (SqlDataAdapter adapter = new SqlDataAdapter(command)) { DataTable dt = new DataTable(); adapter.Fill(dt); return dt; } } } } [DataObjectMethod(DataObjectMethodType.Select)] public static Int32 CountFriends() { using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["Default"].ConnectionString)) { using (SqlCommand command = new SqlCommand("CountFriends", connection)) { command.CommandType = CommandType.StoredProcedure; connection.Open(); return Convert.ToInt32(command.ExecuteScalar()); } } } } There are a few things you'll notice in the preceding snippet, attributes like DataObjectMethod & DataObject - these attributes are simply there to make these methods visible in the control designers, eg Configure Data Source in design view. Also, you'll notice we need to create two stored procedures ViewFriends and CountFriends. ViewFriends require two parameters, maximumRows and startRowIndex, these parameters automatically become required the second we set EnablePaging in our object to true. Now is probably a good time to create some data. Lets create a little table, where we insert the first and last names of friends. CREATE TABLE [dbo].[friends]( [id] [int] IDENTITY(1,1) NOT NULL, [firstname] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, [lastname] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, CONSTRAINT [PK_friends] PRIMARY KEY CLUSTERED ( [id] ASC )WITH (PAD_INDEX = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY] ) ON [PRIMARY] Populate it with some data. INSERT INTO friends(firstname, lastname) VALUES ('Julie', 'Truter') INSERT INTO friends(firstname, lastname) VALUES ('Eugene', 'Stander') INSERT INTO friends(firstname, lastname) VALUES ('Pam', 'Nizar') INSERT INTO friends(firstname, lastname) VALUES ('Alexander', 'Mehlhorn') INSERT INTO friends(firstname, lastname) VALUES ('Roland', 'Cooper') INSERT INTO friends(firstname, lastname) VALUES ('Loren', 'Stevens') INSERT INTO friends(firstname, lastname) VALUES ('Edward', 'Anderson') INSERT INTO friends(firstname, lastname) VALUES ('Wayne', 'Kleynhans') The ViewFriends stored procedure will look like this, notice we use a CTE to aid us in our paging process - this works in SQL 2005 and greater. CREATE PROCEDURE [dbo].[ViewFriends] @maximumRows AS INT, @startRowIndex AS INT AS BEGIN WITH entries AS ( SELECT ROW_NUMBER() OVER (ORDER BY id ASC) AS ROW, id, firstname, lastname FROM friends ) SELECT firstname, lastname FROM entries WHERE ROW BETWEEN @startRowIndex+1 AND (@startRowIndex + @maximumRows) END And the CountFriends like this: CREATE PROCEDURE CountFriends AS BEGIN SELECT COUNT(*) FROM friends END Getting back to our frontend, our pager will look something like this: <asp:DataPager runat="server" ID="dpFriends" PagedControlID="lvFriends" PageSize="3"> <Fields> <asp:NumericPagerField ButtonType="Link" /> </Fields> </asp:DataPager> Notice PagedControlID, this is the control we'll be paging, and PageSize is the number of rows that must be displayed. Finally, our ListView will look like this: <asp:ListView ID="lvFriends" DataSourceID="obsFriends" runat="server" ItemPlaceholderID="phFriends"> <LayoutTemplate> <table> <tr style="background-color: Black; color: White"> <td> Firstname </td> <td> Lastname </td> </tr> <asp:PlaceHolder ID="phFriends" runat="server"></asp:PlaceHolder> </table> </LayoutTemplate> <ItemTemplate> <tr> <td> <%# Eval("firstname") %> </td> <td> <%# Eval("lastname") %> </td> </tr> </ItemTemplate> </asp:ListView> DataSourceID refers to our ObjectDataSource, ItemPlaceholderID to the control within our LayoutTemplate thats going to be substituted, with the values generated within the ItemTemplate.
<asp:ObjectDataSource ID="obsFriends" runat="server" SelectCountMethod="CountFriends" SelectMethod="ViewFriends" TypeName="friends" EnablePaging="true"> </asp:ObjectDataSource>
using System; using System.Data; using System.Configuration; using System.ComponentModel; using System.Data.SqlClient; [DataObject()] public class friends { [DataObjectMethod(DataObjectMethodType.Select)] public static DataTable ViewFriends(Int32 maximumRows, Int32 startRowIndex) { using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["Default"].ConnectionString)) { using (SqlCommand command = new SqlCommand("ViewFriends", connection)) { command.CommandType = CommandType.StoredProcedure; command.Parameters.AddWithValue("@maximumRows", maximumRows); command.Parameters.AddWithValue("@startRowIndex", startRowIndex); using (SqlDataAdapter adapter = new SqlDataAdapter(command)) { DataTable dt = new DataTable(); adapter.Fill(dt); return dt; } } } } [DataObjectMethod(DataObjectMethodType.Select)] public static Int32 CountFriends() { using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["Default"].ConnectionString)) { using (SqlCommand command = new SqlCommand("CountFriends", connection)) { command.CommandType = CommandType.StoredProcedure; connection.Open(); return Convert.ToInt32(command.ExecuteScalar()); } } } }
CREATE TABLE [dbo].[friends]( [id] [int] IDENTITY(1,1) NOT NULL, [firstname] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, [lastname] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, CONSTRAINT [PK_friends] PRIMARY KEY CLUSTERED ( [id] ASC )WITH (PAD_INDEX = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY] ) ON [PRIMARY]
INSERT INTO friends(firstname, lastname) VALUES ('Julie', 'Truter') INSERT INTO friends(firstname, lastname) VALUES ('Eugene', 'Stander') INSERT INTO friends(firstname, lastname) VALUES ('Pam', 'Nizar') INSERT INTO friends(firstname, lastname) VALUES ('Alexander', 'Mehlhorn') INSERT INTO friends(firstname, lastname) VALUES ('Roland', 'Cooper') INSERT INTO friends(firstname, lastname) VALUES ('Loren', 'Stevens') INSERT INTO friends(firstname, lastname) VALUES ('Edward', 'Anderson') INSERT INTO friends(firstname, lastname) VALUES ('Wayne', 'Kleynhans')
CREATE PROCEDURE [dbo].[ViewFriends] @maximumRows AS INT, @startRowIndex AS INT AS BEGIN WITH entries AS ( SELECT ROW_NUMBER() OVER (ORDER BY id ASC) AS ROW, id, firstname, lastname FROM friends ) SELECT firstname, lastname FROM entries WHERE ROW BETWEEN @startRowIndex+1 AND (@startRowIndex + @maximumRows) END
CREATE PROCEDURE CountFriends AS BEGIN SELECT COUNT(*) FROM friends END
<asp:DataPager runat="server" ID="dpFriends" PagedControlID="lvFriends" PageSize="3"> <Fields> <asp:NumericPagerField ButtonType="Link" /> </Fields> </asp:DataPager>
<asp:ListView ID="lvFriends" DataSourceID="obsFriends" runat="server" ItemPlaceholderID="phFriends"> <LayoutTemplate> <table> <tr style="background-color: Black; color: White"> <td> Firstname </td> <td> Lastname </td> </tr> <asp:PlaceHolder ID="phFriends" runat="server"></asp:PlaceHolder> </table> </LayoutTemplate> <ItemTemplate> <tr> <td> <%# Eval("firstname") %> </td> <td> <%# Eval("lastname") %> </td> </tr> </ItemTemplate> </asp:ListView>
Codebooth my semi-community site etc (work in progress)
The company I'am currently working for as software developer.
a Parallel reference of programming languages 2009-09-10 12:48:23
a tutorial explaining how to develop a simple login using PHP and MySQL 2009-09-05 18:26:47
An article looking at adding some kind of event driven model to PHP 5 2008-07-28 12:48:09
It is very simple creating your own rss reader, the following article looks at a few methods of doing this. 2008-06-23 13:18:25
A quick reference about working with dropdown boxes (select element) in javascript. 2007-02-17 16:36:41
Collection of funny programming articles 2006-10-08 14:23:43