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<h1>Deleting Collections</h1><script>
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</script><p>As it was discussed in
<a href="../working_with_structured_objects/deleting_structured_objects.html" class="wikiLink">Deleting Structured Objects</a> chapter,
deleting a top-level object does not mean deleting all of the member objects.
The same rule applies for collections. The recommendation would be to use
cascadeOnDelete setting for a collection, which should be deleted with all its
members.</p><p>For the following example we will use <a href="example_classes.html" class="wikiLink">DataObject and
ListObject</a> classes. The database will be filled up with the
<a href="filling_the_database.html" class="wikiLink">FillUpDb</a> method. <br></p>
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<div class="FormattedSourceCode"><div class="fscHeader"><span class="fscFileName">ListDeletingExample.cs: <span class="fscMemberName">DeleteTest</span></span></div><div class="fscCode"><pre ID="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66"><div><!--
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--><span style="color: #008080;">01</span><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Open_Text').style.display='inline';"/><span style="color: #0000FF;">private</span><span style="color: #000000;"> </span><span style="color: #0000FF;">static</span><span style="color: #000000;"> </span><span style="color: #0000FF;">void</span><span style="color: #000000;"> DeleteTest()</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">...</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_32_1354_Open_Text"><span style="color: #000000;">{
</span><span style="color: #008080;">02</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">//</span><span style="color: #008000;"> set cascadeOnDelete in order to delete member objects</span><span style="color: #008000;">
</span><span style="color: #008080;">03</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> IConfiguration configuration </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.NewConfiguration();
</span><span style="color: #008080;">04</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> configuration.ObjectClass(</span><span style="color: #0000FF;">typeof</span><span style="color: #000000;">(ListObject)).CascadeOnDelete(</span><span style="color: #0000FF;">true</span><span style="color: #000000;">);
</span><span style="color: #008080;">05</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> IObjectContainer db </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.OpenFile(configuration , Db4oFileName);
</span><span style="color: #008080;">06</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">try</span><span style="color: #000000;">
</span><span style="color: #008080;">07</span><span style="color: #000000;"><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedSubBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Open_Text').style.display='inline';"/> </span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">...</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_373_745_Open_Text"><span style="color: #000000;">{
</span><span style="color: #008080;">08</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> IList</span><span style="color: #000000;"><</span><span style="color: #000000;">ListObject</span><span style="color: #000000;">></span><span style="color: #000000;"> result </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Query</span><span style="color: #000000;"><</span><span style="color: #000000;">ListObject</span><span style="color: #000000;">></span><span style="color: #000000;">(</span><span style="color: #0000FF;">typeof</span><span style="color: #000000;">(ListObject));
</span><span style="color: #008080;">09</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">if</span><span style="color: #000000;"> (result.Count </span><span style="color: #000000;">></span><span style="color: #000000;"> </span><span style="color: #800080;">0</span><span style="color: #000000;">)
</span><span style="color: #008080;">10</span><span style="color: #000000;"><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedSubBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Open_Text').style.display='inline';"/> </span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">...</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_514_731_Open_Text"><span style="color: #000000;">{
</span><span style="color: #008080;">11</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">//</span><span style="color: #008000;"> retrieve a ListObject</span><span style="color: #008000;">
</span><span style="color: #008080;">12</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> ListObject lo1 </span><span style="color: #000000;">=</span><span style="color: #000000;"> result[</span><span style="color: #800080;">0</span><span style="color: #000000;">];
</span><span style="color: #008080;">13</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">//</span><span style="color: #008000;"> delete the ListObject with all the field objects</span><span style="color: #008000;">
</span><span style="color: #008080;">14</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> db.Delete(lo1);
</span><span style="color: #008080;">15</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockEnd.gif" align="top"/> }</span></span><span style="color: #000000;">
</span><span style="color: #008080;">16</span><span style="color: #000000;"><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedSubBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Open_Text').style.display='inline';"/> }</span></span><span style="color: #000000;"> </span><span style="color: #0000FF;">finally</span><span style="color: #000000;"> </span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">...</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_754_794_Open_Text"><span style="color: #000000;">{
</span><span style="color: #008080;">17</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> db.Close();
</span><span style="color: #008080;">18</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockEnd.gif" align="top"/> }</span></span><span style="color: #000000;">
</span><span style="color: #008080;">19</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">//</span><span style="color: #008000;"> check ListObjects and DataObjects in the database</span><span style="color: #008000;">
</span><span style="color: #008080;">20</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> db </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.OpenFile(Db4oFileName);
</span><span style="color: #008080;">21</span><span style="color: #000000;"><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedSubBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Open_Text').style.display='inline';"/> </span><span style="color: #0000FF;">try</span><span style="color: #000000;"> </span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">...</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_929_1292_Open_Text"><span style="color: #000000;">{
</span><span style="color: #008080;">22</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> IList</span><span style="color: #000000;"><</span><span style="color: #000000;">ListObject</span><span style="color: #000000;">></span><span style="color: #000000;"> listObjects </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Query</span><span style="color: #000000;"><</span><span style="color: #000000;">ListObject</span><span style="color: #000000;">></span><span style="color: #000000;">(</span><span style="color: #0000FF;">typeof</span><span style="color: #000000;">(ListObject));
</span><span style="color: #008080;">23</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> Console.WriteLine(</span><span style="color: #800000;">"</span><span style="color: #800000;">ListObjects in the database: </span><span style="color: #800000;">"</span><span style="color: #000000;"> </span><span style="color: #000000;">+</span><span style="color: #000000;"> listObjects.Count);
</span><span style="color: #008080;">24</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> IList</span><span style="color: #000000;"><</span><span style="color: #000000;">DataObject</span><span style="color: #000000;">></span><span style="color: #000000;"> dataObjects </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Query</span><span style="color: #000000;"><</span><span style="color: #000000;">DataObject</span><span style="color: #000000;">></span><span style="color: #000000;">(</span><span style="color: #0000FF;">typeof</span><span style="color: #000000;">(DataObject));
</span><span style="color: #008080;">25</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> Console.WriteLine(</span><span style="color: #800000;">"</span><span style="color: #800000;">DataObjects in the database: </span><span style="color: #800000;">"</span><span style="color: #000000;"> </span><span style="color: #000000;">+</span><span style="color: #000000;"> dataObjects.Count);
</span><span style="color: #008080;">26</span><span style="color: #000000;"><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedSubBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Open_Text').style.display='inline';"/> }</span></span><span style="color: #000000;"> </span><span style="color: #0000FF;">finally</span><span style="color: #000000;"> </span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">...</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingCS.ZipsListDeletingExample.Cs_ListDeletingExample.Cs_DeleteTest_594_66_1301_1344_Open_Text"><span style="color: #000000;">{
</span><span style="color: #008080;">27</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> db.Close();
</span><span style="color: #008080;">28</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedSubBlockEnd.gif" align="top"/> }</span></span><span style="color: #000000;">
</span><span style="color: #008080;">29</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedBlockEnd.gif" align="top"/> }</span></span></div></pre></div></div>
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<div class="FormattedSourceCode"><div class="fscHeader"><span class="fscFileName">ListDeletingExample.vb: <span class="fscMemberName">DeleteTest</span></span></div><div class="fscCode"><pre ID="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66"><div><!--
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--><span style="color: #008080;">01</span><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Open_Text').style.display='inline';"/><span style="color: #0000FF;">Private</span><span style="color: #000000;"> </span><span style="color: #0000FF;">Shared</span><span style="color: #000000;"> </span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">Sub DeleteTest()</span><span id="ResourcesReferenceObject_LifecycleDelete_BehaviorListDeletingVB.ZipsListDeletingExample.Vb_ListDeletingExample.Vb_DeleteTest_722_66_15_1418_Open_Text"><span style="color: #0000FF;">Sub</span><span style="color: #000000;"> DeleteTest()
</span><span style="color: #008080;">02</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">'</span><span style="color: #008000;"> set cascadeOnDelete in order to delete member objects</span><span style="color: #008000;">
</span><span style="color: #008080;">03</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> configuration </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IConfiguration </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.NewConfiguration()
</span><span style="color: #008080;">04</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> configuration.ObjectClass(</span><span style="color: #0000FF;">GetType</span><span style="color: #000000;">(ListObject)).CascadeOnDelete(</span><span style="color: #0000FF;">True</span><span style="color: #000000;">)
</span><span style="color: #008080;">05</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> db </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IObjectContainer </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.OpenFile(configuration, Db4oFileName)
</span><span style="color: #008080;">06</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Try</span><span style="color: #000000;">
</span><span style="color: #008080;">07</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> result </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IList(</span><span style="color: #0000FF;">Of</span><span style="color: #000000;"> ListObject) </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Query(</span><span style="color: #0000FF;">Of</span><span style="color: #000000;"> ListObject)(</span><span style="color: #0000FF;">GetType</span><span style="color: #000000;">(ListObject))
</span><span style="color: #008080;">08</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">If</span><span style="color: #000000;"> result.Count </span><span style="color: #000000;">></span><span style="color: #000000;"> </span><span style="color: #800080;">0</span><span style="color: #000000;"> </span><span style="color: #0000FF;">Then</span><span style="color: #000000;">
</span><span style="color: #008080;">09</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">'</span><span style="color: #008000;"> retrieve a ListObject</span><span style="color: #008000;">
</span><span style="color: #008080;">10</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> lo1 </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> ListObject </span><span style="color: #000000;">=</span><span style="color: #000000;"> result(</span><span style="color: #800080;">0</span><span style="color: #000000;">)
</span><span style="color: #008080;">11</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">'</span><span style="color: #008000;"> delete the ListObject with all the field objects</span><span style="color: #008000;">
</span><span style="color: #008080;">12</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> db.Delete(lo1)
</span><span style="color: #008080;">13</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">End</span><span style="color: #000000;"> </span><span style="color: #0000FF;">If</span><span style="color: #000000;">
</span><span style="color: #008080;">14</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Finally</span><span style="color: #000000;">
</span><span style="color: #008080;">15</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> db.Close()
</span><span style="color: #008080;">16</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">End</span><span style="color: #000000;"> </span><span style="color: #0000FF;">Try</span><span style="color: #000000;">
</span><span style="color: #008080;">17</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #008000;">'</span><span style="color: #008000;"> check ListObjects and DataObjects in the database</span><span style="color: #008000;">
</span><span style="color: #008080;">18</span><span style="color: #008000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/></span><span style="color: #000000;"> db </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.OpenFile(Db4oFileName)
</span><span style="color: #008080;">19</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Try</span><span style="color: #000000;">
</span><span style="color: #008080;">20</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> listObjects </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IList(</span><span style="color: #0000FF;">Of</span><span style="color: #000000;"> ListObject) </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Query(</span><span style="color: #0000FF;">Of</span><span style="color: #000000;"> ListObject)(</span><span style="color: #0000FF;">GetType</span><span style="color: #000000;">(ListObject))
</span><span style="color: #008080;">21</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> Console.WriteLine(</span><span style="color: #800000;">"</span><span style="color: #800000;">ListObjects in the database: </span><span style="color: #800000;">"</span><span style="color: #000000;"> </span><span style="color: #000000;">+</span><span style="color: #000000;"> listObjects.Count.ToString())
</span><span style="color: #008080;">22</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> dataObjects </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IList(</span><span style="color: #0000FF;">Of</span><span style="color: #000000;"> DataObject) </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Query(</span><span style="color: #0000FF;">Of</span><span style="color: #000000;"> DataObject)(</span><span style="color: #0000FF;">GetType</span><span style="color: #000000;">(DataObject))
</span><span style="color: #008080;">23</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> Console.WriteLine(</span><span style="color: #800000;">"</span><span style="color: #800000;">DataObjects in the database: </span><span style="color: #800000;">"</span><span style="color: #000000;"> </span><span style="color: #000000;">+</span><span style="color: #000000;"> dataObjects.Count.ToString())
</span><span style="color: #008080;">24</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Finally</span><span style="color: #000000;">
</span><span style="color: #008080;">25</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> db.Close()
</span><span style="color: #008080;">26</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">End</span><span style="color: #000000;"> </span><span style="color: #0000FF;">Try</span><span style="color: #000000;">
</span><span style="color: #008080;">27</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedBlockEnd.gif" align="top"/> </span><span style="color: #0000FF;">End Sub</span></span></div></pre></div></div>
</span>
Please, remember that there is no referential
integrity check on delete: deleted objects might be referenced from elsewhere
in your code.
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This revision (4) was last Modified 2007-05-04T12:56:43 by Tetyana.
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