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<h1>Basics Operations & Concepts</h1>
<p>This topic gives you an overview of the most important and basic operations of db4o. First add db4o to your project. db4o doesn't need a complex setup. It's just a library which you can add to your project. <a href="basics/getting_started.htm" target="" title="" alt="" class="MCXref">See "Getting Started"</a></p>
<h2>Basic Operations</h2>
<p>The basic operations are, not surprising, storing, updating, querying and deleting objects. <a href="basics/object_container.htm" target="" title="" alt="" class="MCXref">See "The Basic Operations"</a></p>
<div class="codesnippet" MadCap:conditions="Primary.c#">
<pre class="prettyprint" xml:space="preserve">using(IObjectContainer container = Db4oEmbedded.OpenFile("databaseFile.db4o"))
{
// store a new pilot
Pilot pilot = new Pilot("Joe");
container.Store(pilot);
// query for pilots
var pilots = from Pilot p in container
where p.Name.StartsWith("Jo")
select p;
// update pilot
Pilot toUpdate = pilots.First();
toUpdate.Name = "New Name";
container.Store(toUpdate);
// delete pilot
container.Delete(toUpdate);
} </pre>
<div class="codesnippet-meta">Db4oBasics.cs: The basic operations
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<div class="codesnippet" MadCap:conditions="Primary.VB.NET">
<pre class="prettyprint lang-vb" MadCap:conditions="Primary.Online" xml:space="preserve">Using container As IObjectContainer = Db4oEmbedded.OpenFile("databaseFile.db4o")
' store a new pilot
Dim pilot As New Pilot("Joe")
container.Store(pilot)
' query for pilots
Dim pilots = From p As Pilot In container Where p.Name.StartsWith("Jo")
' update pilot
Dim toUpdate As Pilot = pilots.First()
toUpdate.Name = "New Name"
container.Store(toUpdate)
' delete pilot
container.Delete(toUpdate)
End Using</pre>
<div class="codesnippet-meta">Db4oBasics.vb: The basic operations
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<p>For more information about queries: <a href="basics/querying.htm" target="" title="" alt="" class="MCXref">See "Querying"</a></p>
<h2>Basic Concepts</h2>
<p>There are some basic concepts which are used in db4o. Understanding them helps to understand how db4o behaves. Some behaviors are common behaviors which you expect from a database, like transactions and <span class="MCPopup"><a href="javascript:void(0);" class="MCPopupSpot" onclick="FMCPopup( event, this ); return false;" MadCap:src="basics/acid_and_transactions.htm">ACID<img style="border: none;margin-left: 5px;" src="SkinSupport/ExpandingClosed.gif" MadCap:altsrc="SkinSupport/ExpandingOpen.gif" class="MCExpandingIcon" onload="if ( typeof( FMCPreloadImage ) == 'function' ) { FMCPreloadImage( 'SkinSupport/ExpandingOpen.gif' ); }" /></a></span> properties. <a href="basics/acid_and_transactions.htm" target="" title="" alt="" class="MCXref">See "ACID Properties And Transactions"</a></p>
<p>db4o manages objects by identity. This means db4o doesn't need additional id-field on your object. <a href="basics/identity_concept.htm" target="" title="" alt="" class="MCXref">See "Identity Concept"</a></p>
<p style="font-weight: normal;">Other concepts are more unique to db4o. For example the activation concept, which controls which objects are loaded from the storage to memory. <a href="basics/activation.htm" target="" title="" alt="" class="MCXref">See "Activation Concept"</a>. The same principals are also applied when updating (<a href="basics/update_concept.htm" target="" title="" alt="" class="MCXref">See "Update Concept"</a> ) or deletion objects (<a href="basics/delete_behavior.htm" target="" title="" alt="" class="MCXref">See "Delete Behavior"</a></p>
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