Sending the LINQ To SQL log to log4net
DataContext Log Property can be used to print generated SQL query or command in the console window as shown below:
If you want to print the SQL query in DebugView or VS Output window you may use DebugWriter class(by Kris Vandermotten) .The usage of the class is pretty simple ...
db.Log = new DebugWriter();
I wrote a small class that help you redirect DataContext messages to log4net .I've changed the DebugWriter and call it Log4NetWriter . The usage is still simple
db.Log = new Log4NetWriter(this.GetType());
As result you get formatted log4net messages that can be send to any log4net appender .
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using log4net;
using log4net.Core;
using log4net.Repository.Hierarchy;
namespace Devintelligence.Data
{
public class Log4NetWriter : TextWriter
{
/// <summary>
/// Initializes a new instance of the <see cref="Log4NetWriter"/> class.
/// </summary>
/// <param name="type">The type.</param>
public Log4NetWriter(Type type):this(type,Level.Debug)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="Log4NetWriter"/> class.
/// </summary>
/// <param name="type">The logger source type.</param>
/// <param name="level">The log4net log level.</param>
public Log4NetWriter(Type type, Level level)
{
logSrcType = type;
this.level = level;
open = true;
}
/// <summary>
/// Releases the unmanaged resources used by the <see cref="T:System.IO.TextWriter"/> and optionally releases the managed resources.
/// </summary>
/// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.</param>
protected override void Dispose(bool disposing)
{
open = false;
base.Dispose(disposing);
}
/// <summary>
/// Writes a character to the text stream.
/// </summary>
/// <param name="value">The character to write to the text stream.</param>
/// <exception cref="T:System.ObjectDisposedException">The <see cref="T:System.IO.TextWriter"/> is closed. </exception>
/// <exception cref="T:System.IO.IOException">An I/O error occurs. </exception>
public override void Write(char value)
{
if (!open)
{
throw new ObjectDisposedException(null);
}
Log(value.ToString());
}
/// <summary>
/// Writes a string to the text stream.
/// </summary>
/// <param name="value">The string to write.</param>
/// <exception cref="T:System.ObjectDisposedException">The <see cref="T:System.IO.TextWriter"/> is closed. </exception>
/// <exception cref="T:System.IO.IOException">An I/O error occurs. </exception>
public override void Write(string value)
{
if (!open)
{
throw new ObjectDisposedException(null);
}
if (value != null)
{
Log(value);
}
}
/// <summary>
/// Writes a subarray of characters to the text stream.
/// </summary>
/// <param name="buffer">The character array to write data from.</param>
/// <param name="index">Starting index in the buffer.</param>
/// <param name="count">The number of characters to write.</param>
/// <exception cref="T:System.ArgumentException">The buffer length minus <paramref name="index"/> is less than <paramref name="count"/>. </exception>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="buffer"/> parameter is null. </exception>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// <paramref name="index"/> or <paramref name="count"/> is negative. </exception>
/// <exception cref="T:System.ObjectDisposedException">The <see cref="T:System.IO.TextWriter"/> is closed. </exception>
/// <exception cref="T:System.IO.IOException">An I/O error occurs. </exception>
public override void Write(char[] buffer, int index, int count)
{
if (!open)
{
throw new ObjectDisposedException(null);
}
if (buffer == null || index < 0 || count < 0 || buffer.Length - index < count)
{
base.Write(buffer, index, count); // delegate throw exception to base class
}
Log( new string(buffer, index, count));
}
/// <summary>
/// When overridden in a derived class, returns the <see cref="T:System.Text.Encoding"/> in which the output is written.
/// </summary>
/// <value></value>
/// <returns>The Encoding in which the output is written.</returns>
public override Encoding Encoding
{
get
{
if (encoding == null)
{
encoding = new UnicodeEncoding(false, false);
}
return encoding;
}
}
/// <summary>
/// Writes a message to log4net
/// </summary>
/// <param name="message"></param>
private void Log( string message )
{
Hierarchy hierarchy = ((Hierarchy)LogManager.GetRepository());
ILoggerFactory loggerFactory = ((Hierarchy)LogManager.GetRepository()).LoggerFactory;
Logger logger = hierarchy.GetLogger(logSrcType.FullName, loggerFactory);
logger.Log(level, message, null);
}
private bool open;
private static UnicodeEncoding encoding;
private readonly Level level;
private Type logSrcType;
}
}