# VBForums CodeBank > CodeBank - C# >  Custom Trace Listener - Multiple Traces and writing to a sql table

## wild_bill

I've put together a short example of a trace listener I created.  For this sample all messages are written to a SQL server table using the custom listener.  Any error messages are also written to the console window.

My sample console application that creates trace messages


```
    class CS_ConsoleApp
    {
        static void Main(string[] args)
        {
            for (int i = 0; i < 20; i++)
            {
                if (i >= 0 & i <= 2)
                {
                    Trace.TraceError("{0} FOUND!!!!!  THIS IS TERRIBLE!!!!.", i);
                }
                else
                {
                    if (isPrime(i))
                    {
                        Trace.TraceInformation("{0} is prime.", i);
                    }
                    else
                    {
                        Trace.TraceWarning("{0} is not prime.", i);
                    }
                }
            }

            Console.ReadLine();
        }

        static bool isPrime(int number)
        {
            if (number % 2 == 0) return false; //Even number     

            for (int i = 3; i < number; i += 2)
            {
                if (number % i == 0) return false;
            }

            return true;

        }
```

App.Config


```
<?xml version="1.0" encoding="utf-8" ?>
<configuration>

  <system.diagnostics>

    <trace autoflush="true">
      <!-- Trace filters can be set to Information, Warning, Error-->
      <listeners>
        <!-- Write Messages to Console -->
        <add name="consoleListener" type="System.Diagnostics.ConsoleTraceListener">
          <filter type="System.Diagnostics.EventTypeFilter"
                  initializeData="Error" />
        </add>
        <!-- Implement Custom Listener -->
        <add name="sqlListener"
            type="SFHP.Automation.Tracing.SqlListener, Tracing, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null">
          <filter type="System.Diagnostics.EventTypeFilter"
                  initializeData="Information"/>
        </add>
      </listeners>
    </trace>
  </system.diagnostics>
</configuration>
```

The class I created to handle (listen) for the messages


```
    public class SqlListener : TraceListener
    {
        public override void TraceEvent(TraceEventCache eventCache, string source, TraceEventType eventType, int id, string format, params object[] args)
        {
            const string commandText = "INSERT INTO dbo.Logging(host, application, level, logInfo) VALUES (@host, @application, @level, @logInfo)";
            if (this.Filter.ShouldTrace(eventCache, source, eventType, id, format, args, null, null) == true)
            {


                using (var con = new SqlConnection("server=SomeServer;database=SomeDatabase;trusted_connection=true"))
                {
                    con.Open();
                    using (var cmd = new SqlCommand(commandText, con))
                    {
                        cmd.Parameters.Add("@host", System.Data.SqlDbType.VarChar).Value = System.Environment.MachineName;
                        cmd.Parameters.Add("@application", System.Data.SqlDbType.VarChar).Value = source; ;
                        cmd.Parameters.Add("@level", System.Data.SqlDbType.VarChar).Value = eventType.ToString();
                        cmd.Parameters.Add("@logInfo", System.Data.SqlDbType.VarChar).Value = string.Format(format, args);

                        cmd.ExecuteNonQuery();
                    }
                }
            }
        }

        public override void Write(string message)
        {
            throw new System.NotImplementedException();
        }

        public override void WriteLine(string message)
        {
            throw new System.NotImplementedException();
        }
    }
```

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