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<h1>Example db4o UUID</h1>
<p>This example demonstrates how you can use db4o-UUIDs to identify objects across objects containers. Take a look advantages and disadvantages of db4o-UUIDs: <a href="comparison_of_ids.htm" target="" title="" alt="" class="MCXref" xrefformat="See "{paratext}"">See "Comparison Of Different IDs"</a></p>
<p>First you need to enable db4o-UUIDs in order to use it.</p>
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<pre class="prettyprint" xml:space="preserve">configuration.File.GenerateUUIDs = ConfigScope.Globally;</pre>
<div class="codesnippet-meta">Db4oUuidExample.cs: db4o-uuids need to be activated
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<pre class="prettyprint lang-vb" MadCap:conditions="Primary.Online" xml:space="preserve">configuration.File.GenerateUUIDs = ConfigScope.Globally</pre>
<div class="codesnippet-meta">Db4oUuidExample.vb: db4o-uuids need to be activated
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<p>With UUIDs turned on, db4o will create an UUID for each stored object. So you can get the UUID of the object from the object-container.</p>
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<pre class="prettyprint" xml:space="preserve">Db4oUUID uuid = container.Ext().GetObjectInfo(obj).GetUUID();</pre>
<div class="codesnippet-meta">Db4oUuidExample.cs: get the db4o-uuid
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<pre class="prettyprint lang-vb" MadCap:conditions="Primary.Online" xml:space="preserve">Dim uuid As Db4oUUID = container.Ext().GetObjectInfo(obj).GetUUID()</pre>
<div class="codesnippet-meta">Db4oUuidExample.vb: get the db4o-uuid
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<p>Getting a object by its UUID is also easy. First you get the object from the container. Unlike queries this won't <a href="../../basics/activation.htm">activate</a> your object. So you have to do it explicitly.</p>
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<pre class="prettyprint" xml:space="preserve">object objectForId = container.Ext().GetByUUID(idForObject);
// getting by uuid doesn't activate the object
// so you need to do it manually
container.Ext().Activate(objectForId);</pre>
<div class="codesnippet-meta">Db4oUuidExample.cs: get an object by a db4o-uuid
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<pre class="prettyprint lang-vb" MadCap:conditions="Primary.Online" xml:space="preserve">Dim objForId As Object = container.Ext().GetByUUID(idForObject)
' getting by uuid doesn't activate the object
' so you need to do it manually
container.Ext().Activate(objForId)</pre>
<div class="codesnippet-meta">Db4oUuidExample.vb: get an object by a db4o-uuid
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