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<h1><a name="kanchor107"></a>Isolation in Web-Applications</h1>
<p>In most web-application multiple concurrent request are processes. You want to isolate the request from each other. db4o supports <a href="../../basics/acid_and_transactions.htm">transactions</a>, which are perfect for this kind of isolation. Each unit of work gets its own transaction, for example each request. You can create a new session object container for this purpose. Such a session-container brings its own transaction and reference-system. This ensures that the session container is isolated from other operations on the database.</p>
<div class="codesnippet" MadCap:conditions="Primary.c#">
<pre class="prettyprint" xml:space="preserve">using (IObjectContainer rootContainer = Db4oEmbedded.OpenFile(DatabaseFileName))
{
// open the db4o-session. For example at the beginning for a web-request
using (IObjectContainer session = rootContainer.Ext().OpenSession())
{
// do the operations on the session-container
session.Store(new Person("Joe"));
}
}</pre>
<div class="codesnippet-meta">Db4oSessions.cs: Session object container
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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 rootContainer As IObjectContainer = Db4oEmbedded.OpenFile(DatabaseFileName)
' open the db4o-session. For example at the beginning for a web-request
Using session As IObjectContainer = rootContainer.Ext().OpenSession()
' do the operations on the session-container
session.Store(New Person("Joe"))
End Using
End Using</pre>
<div class="codesnippet-meta">Db4oSessions.vb: Session object container
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<p>Or you can use embedded clients when your <a href="../../client-server/embedded.htm">embedded clients</a>.</p>
<div class="codesnippet" MadCap:conditions="Primary.c#">
<pre class="prettyprint" xml:space="preserve">using (IObjectServer server = Db4oClientServer.OpenServer(DatabaseFileName, 0))
{
// open the db4o-embedded client. For example at the beginning for a web-request
using (IObjectContainer container = server.OpenClient())
{
// do the operations on the session-container
container.Store(new Person("Joe"));
}
}</pre>
<div class="codesnippet-meta">Db4oSessions.cs: Embedded client
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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 server As IObjectServer = Db4oClientServer.OpenServer(DatabaseFileName, 0)
' open the db4o-embedded client. For example at the beginning for a web-request
Using container As IObjectContainer = server.OpenClient()
' do the operations on the session-container
container.Store(New Person("Joe"))
End Using
End Using</pre>
<div class="codesnippet-meta">Db4oSessions.vb: Embedded client
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