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<h1 class="dtH1">Calling a custom stored procedure</h1>
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<p>One scenario for developers is to add EasyObjects.NET to an existing
application. The existing application may include existing stored procedures
that contain business logic. EasyObjects.NET is designed to help this
process, by giving developers methods to call any custom stored procedures.</p>
<h2>Typical Goals</h2>
<p>In this scenario, you want to call a custom stored procedure in the
database.</p>
<p>These goals can be summarized as follows: </p>
<ul>
<li>You want to retrieve data from a custom stored procedure.
</li>
<li>You may optionally pass IN parameters from the business object to
the procedure.
</li>
<li>You may optionally load the business object with the results of the
procedure.</li>
<li>You may optionally process any OUT parameters from the procedure.</li>
</ul>
<h2>Solution</h2>
<p>Use the <b>LoadFromSql</b> method provided by the <b>
EasyObject</b> class to call a stored procedure and load the business object
with the results. Use the <b>LoadFromSqlNoExec</b> method to call the stored
procedure without affecting the contents of the business class.</p>
<h2>Using LoadFromSql</h2>
<p>The following code shows how to use the <b>LoadFromSql</b> method.</p>
<p>[C#]</p>
<!-- code formatted by http://manoli.net/csharpformat/ -->
<pre class="csharpcode">
public virtual bool TenMostExpensiveProducts ()
{
// Create the Database object, using the default database service. The
// default database service is determined through configuration.
Database db = GetDatabase();
string sqlCommand = this.SchemaStoredProcedureWithSeparator + "[Ten Most Expensive Products]";
DBCommandWrapper dbCommandWrapper = db.GetStoredProcCommandWrapper(sqlCommand);
// Add procedure parameters
return base.LoadFromSql(dbCommandWrapper);
}
</pre>
<p>[VB]</p>
<!-- code formatted by http://manoli.net/csharpformat/ -->
<pre class="csharpcode">
Public Overridable Function TenMostExpensiveProducts() As Boolean
' Create the Database object, using the default database service. The
' default database service is determined through configuration.
Dim db As Database = GetDatabase()
Dim sqlCommand As String = Me.SchemaStoredProcedureWithSeparator + "Ten Most Expensive Products"
Dim dbCommandWrapper As DBCommandWrapper = db.GetStoredProcCommandWrapper(sqlCommand)
' Add procedure parameters
Return MyBase.LoadFromSql(dbCommandWrapper)
End Function
</pre>
<h2>Usage Notes</h2>
<p>The <b>LoadFromSql</b> method returns a Boolean value indicating whether
any rows were returned from the stored procedure. You can substitute inline
SQL instead of calling a stored procedure by calling <b>
GetSqlStringCommandWrapper</b> and removing the <b>
SchemaStoredProcedureWithSeparator</b> call.</p>
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<h4 class="dtH4">See also</h4>
<p>
<a href="developapps-scenarios.htm">
Key Scenarios</a>
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