System.Data.IDataReader Interface

Contents

Overview
Syntax
Properties
Methods
Example
See Also

Overview

The System.Data.IDataReader interface provides a way of reading a forward-only stream of data rows from a data source. It is implemented by data providers such as SqlDataReader and OleDbDataReader.

Syntax

public interface IDataReader : IDisposable, IDataRecord
{
    // Properties
    int Depth { get; }
    bool IsClosed { get; }
    int RecordsAffected { get; }
    int FieldCount { get; }

    // Methods
    void Close();
    DataTable GetSchemaTable();
    bool NextResult();
    bool Read();
    // ... inherited members from IDataRecord
}

Properties

Property	Type	Description
`Depth`	int	Gets the depth of nesting for tables in the data source.
`FieldCount`	int	Gets the number of columns in the current row.
`IsClosed`	bool	Indicates whether the `IDataReader` is closed.
`RecordsAffected`	int	Gets the number of rows changed, inserted, or deleted by execution of the SQL statement.

Methods

Method	Signature	Description
`Close`	void Close()	Closes the `IDataReader` object.
`Read`	bool Read()	Advances the reader to the next record.
`NextResult`	bool NextResult()	Advances the reader to the next result set.
`GetSchemaTable`	DataTable GetSchemaTable()	Retrieves schema information for the column metadata.

Example

This example shows how to use SqlDataReader, which implements IDataReader, to read data from a SQL Server database.

using System;
using System.Data;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connString = "Data Source=.;Initial Catalog=Northwind;Integrated Security=True";
        using (SqlConnection conn = new SqlConnection(connString))
        {
            conn.Open();
            using (SqlCommand cmd = new SqlCommand("SELECT ProductID, ProductName FROM Products", conn))
            using (IDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    int id   = reader.GetInt32(0);
                    string name = reader.GetString(1);
                    Console.WriteLine($"{id}: {name}");
                }
            }
        }
    }
}