# SQL Trace
To save the SQL statements in a file the following code needs to be part of app.config or web.config:
<system.diagnostics>
<sources>
<source name="System.ServiceModel" switchValue="Error">
<listeners>
<add name="xmlTrace" />
</listeners>
</source>
<source name="System.ServiceModel.MessageLogging" switchValue="Verbose">
<listeners>
<add name="xmlTrace" />
</listeners>
</source>
</sources>
<sharedListeners>
<add name="xmlTrace" type="System.Diagnostics.XmlWriterTraceListener" initializeData="C:\temp\client_verbose.svclog" />
</sharedListeners>
<trace autoflush="true">
<listeners>
<add name="xmlDataTrace" traceOutputOptions="Callstack,DateTime,LogicalOperationStack,ProcessId,ThreadId,Timestamp" type="System.Diagnostics.XmlWriterTraceListener" initializeData="C:\temp\client_data_verbose.svclog" />
</listeners>
</trace>
</system.diagnostics>
In the specified file (in this example ‘C: \ temp \ client_verbose.svclog’), the SQL statements will be logged. This file can be read with SvcTraceViewer (can be found in the Windows SDK, but also in the Invantive tools).