Using the .NET DataView Object

Using the .NET DataView Object

When building database driven web applications, presentation of data becomes a key component in your web forms. The common problem that arises is that no two users want to view their data the same way. One user wants to see only certain data; another user wants the data sorted by date ascending while another may only want to see data from the past week. The possibilities are literally endless.

As a developer, how do you cover all the scenarios? The answer is you really can’t, what you can do however is offer enough flexibility in data filtering to allow the user to customize their presentation themselves. And depending on what components you are implementing in your application, the DataView object is a good solution to provide this type of filtering.

In this tutorial we’ll look at a basic ASP.NET application that implements data column filtering as well as row state filtering. We’ll use a DataGrid component to search a column for data that matches a search pattern, thus filtering the user’s view. And we’ll also see how we can use the DataView to show only newly added rows; a pattern which can also be applied to edited or deleted rows easily.

We’ll need a sample database to work with so we’ll use the Northwind database which comes with all versions of SQL server, including MSDE. If you do not have access to SQL server you can simply link the tutorial example to any database of your choice and skip the database configuration section.

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Securely Locking Down ASP.NET Web Services

Securely Locking Down ASP.NET Web Services

During this tutorial we will build 2 separate ASP.NET applications: One to implement the Web Service itself, and one to implement the consumer application which uses the Web Service. By having 2 applications we can effectively simulate the service/consumer pattern which would be found in a real world application, even though in our case both applications will be running on the same machine.

The demonstration Web Service will simply provide several test services which we can call from the consumer. The purpose behind these methods is not their functionality but rather to simply have something to execute. The focus of this tutorial is how to secure the service once it’s built.

We’ll then implement a consumer ASP.NET application and show how we can gain access to the Web Service even thought it’s been completely secured and locked down.

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ASP.NET DataSet Tips & Tricks

Technically part of the ADO.NET object library, the DataSet is one of the most fundamental and widely used data objects in the .NET framework. Used as an in-memory representation of database/XML data, it supports a plethora of handy methods, properties and contains various other object references for working with tables, rows, columns, relationships and more.

Because the DataSet supports so many features and contains so many references to other objects in the ADO.NET library, it can take quite some time to figure out just what is available to you as a developer when working with this object.

The DataSet object is also directly bindable as a data source on the various GUI components that support data binding. It works very nicely with the ASP.NET DataGrid object since both objects were designed to contain data in a similar tabular format.

In this tutorial we’ll focus on 3 key examples to explore some of the lesser known features of the DataSet object. The first example will be manual construction of a DataSet object from scratch. This example will get you familiar with the various object types that compose the DataSet object itself. By constructing the object from scratch you’ll have an idea of what happens when a DataSet is constructed from a database source.

The second example we’ll explore a handy object in ADO.NET that allows you to sort data in the DataSet object by using simple SQL like commands. We’ll build an example that sorts one of the columns of our DataSet from ascending to descending through auto-detection.

In the final example we’ll see how we can index our DataSet by creating a primary key, which then allows us to search through our DataSet for specific rows matching the values on the index we created.

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