ADO.NET Tutorial - Data Readers

Introduction to Data Readers

What are Data Readers?

Data readers are essential for retrieving data from databases, spreadsheets, or other data sources. They allow you to retrieve specific information based on criteria, making it much more efficient than reading entire tables.

There are several types of data readers, each designed for different purposes. Common types include: - Simple Readers: Read a single record. - Multiple Readers: Read multiple records. - Full Readers: Read all records in a table.

The Data Reader Object

The `DataReader` class in .NET represents the data source you are querying.

It has several properties:

  • `reader`: The primary object representing the data source.
  • `state`: Indicates the current state of the reader.
  • `rows`: The number of rows currently being read.
  • `current`: The current row being read.

Basic Usage

Let's create a simple data reader.

// Create a DataReader instance var reader = new DataReader(); // Retrieve the first record reader.Read(); // Get the first row Console.WriteLine("First row:"); Console.WriteLine(reader.GetRow()); }

Step 1: Create a Data Reader

In the example below, we will create a simple data reader that reads a single row.


          using System;
          using System.Data;

          public class Example {
              public static void Main(string[] args) {
                  DataReader reader = new DataReader();
                  reader.Read();
              }
          }