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<title>Loading an EasyObject</title>
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<h1 class="dtH1">Loading an EasyObject</h1>
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<p>A common database task is to load a business object with data from the
database. For example, a reporting application may need to display a list of products
made by the company, or a detail report may need to display just one
product.</p>
<h2>Typical Goals</h2>
<p>In this scenario, you want to retrieve one or multiple rows from a database and
load the EasyObject business object with the results. EasyObjects can
internally hold as many rows</p>
<p>These goals can be summarized as follows: </p>
<ul>
<li>You want to retrieve data for read-only purposes, which typically
means that you want to display it.
</li>
<li>You want to bind to a Web Form control for display.
</li>
<li>You do not need to cache the data. After it is used it is discarded.
</li>
</ul>
<h2>Solution</h2>
<p>Use the <b>LoadByPrimaryKey</b> method provided by the <b>EasyObject</b> class. For example, if the application uses Products, you might pass a product ID to the LoadByPrimaryKey
method to indicate
which individual product to retrieve. Or use the <b>LoadAll</b> method to
retrieve all the products in the database.</p>
<p>The <b>DefaultView</b> property of the <b>EasyObject</b> supports
data binding and can act as a data source for a number of ASP.NET server
controls梖or example, the <strong>DataList</strong> or <strong>DataGrid</strong>
controls. This provides an efficient and flexible way to render the results
in a browser.</p>
<h2>Using LoadByPrimaryKey</h2>
<p>The following code shows how to use the <b>LoadByPrimaryKey</b> method.</p>
<p>[C#]</p>
<!-- code formatted by http://manoli.net/csharpformat/ -->
<pre class="csharpcode">
Products prod = <span class="kwrd">new</span> Products();
<span class="kwrd">if</span> (prod.LoadByPrimaryKey(4))
{
productsGrid.DataSource = prod.DefaultView;
productsGrid.DataBind();
}
</pre>
<p>[VB]</p>
<!-- code formatted by http://manoli.net/csharpformat/ -->
<pre class="csharpcode">
<span class="kwrd">Dim</span> prod <span class="kwrd">As</span> Products = <span class="kwrd">New</span> Products
<span class="kwrd">If</span> prod.LoadByPrimaryKey(4) <span class="kwrd">Then</span>
productsGrid.DataSource = prod.DefaultView
productsGrid.DataBind()
<span class="kwrd">End</span> <span class="kwrd">If</span>
</pre>
<p> </p>
<h2>Using LoadAll</h2>
<p>The following code shows how to use the <b>LoadAll</b> method.</p>
<p>[C#]</p>
<!-- code formatted by http://manoli.net/csharpformat/ -->
<pre class="csharpcode">
Products prod = <span class="kwrd">new</span> Products();
<span class="kwrd">if</span> (prod.LoadAll())
{
productsGrid.DataSource = prod.DefaultView;
productsGrid.DataBind();
}
</pre>
<p>[VB]</p>
<!-- code formatted by http://manoli.net/csharpformat/ -->
<pre class="csharpcode">
<span class="kwrd">Dim</span> prod <span class="kwrd">As</span> Products = <span class="kwrd">New</span> Products
<span class="kwrd">If</span> prod.LoadAll() <span class="kwrd">Then</span>
productsGrid.DataSource = prod.DefaultView
productsGrid.DataBind()
<span class="kwrd">End</span> <span class="kwrd">If</span>
</pre>
<h2>Usage Notes</h2>
<p>The <b>LoadByPrimaryKey</b> method may have different signatures in each
business object, depending on what the primary key is for the database table which
the EasyObject represents.</p>
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<h4 class="dtH4">See also</h4>
<p>
<a href="developapps-scenarios.htm">
Key Scenarios</a>
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