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POOutput parameter is always null with multi.Read
 

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    <p>We are using <a href="http://code.google.com/p/dapper-dot-net/" rel="nofollow">Dapper.Net</a> extensively and are very happy with it. However we have come across an issue when trying to retrieve output parameters from stored procedures using <strong>multi.Read</strong>:</p> <pre><code>var p = new DynamicParameters(); p.Add("@id", id); p.Add("TotalRows", dbType: DbType.Int32, direction: ParameterDirection.Output); using (var multi = cnn.QueryMultiple(string.Format("dbo.[{0}]", spName), p, commandType: CommandType.StoredProcedure)) { int TotalRows = p.Get&lt;int&gt;("@TotalRows"); //This is always null var results = multi.Read&lt;New_Supplier&gt;().ToList&lt;IDBSupplier&gt;(); var areas = multi.Read&lt;node&gt;().ToList&lt;IDBNode&gt;(); var categories = multi.Read&lt;node&gt;().ToList&lt;IDBNode&gt;(); int TotalRows = multi.Read&lt;int&gt;().FirstOrDefault(); // This works } </code></pre> <p>However, if we use the <strong>connection.Query</strong> syntax to get a single resultset the output parameter is populated:</p> <pre><code>var result = cnn.Query&lt;New_Supplier&gt;(string.Format("spname"), p, commandType: CommandType.StoredProcedure).ToList&lt;New_Supplier&gt;(); int TotalRows = p.Get&lt;int&gt;("@TotalRows"); </code></pre> <p>The error is that the sqlValue of AttachedParam on the output parameter in the Dapper DynamicParameters is always null. </p> <p>To work around this we have added the value of the output parameter to the result sets of the stored procedure and are reading it that way. </p> <p>Why is the parameter always null?</p>
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