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PODeleting an entity from a table which is dependent on another table
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  1. PODeleting an entity from a table which is dependent on another table
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    copied!<p>I have 2 tables MachineGroups and Machines. MachineGroups has columns:</p> <ul> <li>MachinegroupID</li> <li>MachineGroupName</li> <li>MachineGroupDesc</li> </ul> <p>And Machines has columns:</p> <ul> <li>MachineGroupID (FK)</li> <li>MachineID</li> <li>MachineName</li> <li>Machinedesc</li> </ul> <p>Now I want to delete a machinegroup but not the ones that have machines in it. So if there are machines it should give an error message.... saying you cannot delete.</p> <p>Here is what I am trying to do.....</p> <pre><code>&lt;asp:GridView ID="GridView1" runat="server" AllowSorting="True" AutoGenerateColumns="False" CellPadding="1" CellSpacing="2" DataSourceID="SqlDataSource1" ForeColor="#333333" GridLines="None" Width="100%" ondatabound="GridView1_DataBound1" onrowdatabound="GridView1_RowDataBound1"&gt; &lt;RowStyle BackColor="#D0D8E8" ForeColor="#333333" Height="35px" /&gt; &lt;Columns&gt; &lt;asp:BoundField DataField="MachineGroupID" HeaderText="MachineGroupID" InsertVisible="False" ReadOnly="True" SortExpression="MachineGroupID" Visible="False" /&gt; &lt;asp:BoundField DataField="MachineGroupName" HeaderText="MachineGroupName" SortExpression="MachineGroupName" /&gt; &lt;asp:BoundField DataField="MachineGroupDesc" HeaderText="MachineGroupDesc" SortExpression="MachineGroupDesc" /&gt; &lt;asp:BoundField DataField="TimeAdded" HeaderText="TimeAdded" SortExpression="TimeAdded" /&gt; &lt;asp:TemplateField HeaderText="CanBeDeleted" SortExpression="CanBeDeleted" Visible="False"&gt; &lt;EditItemTemplate&gt; &lt;asp:CheckBox ID="CheckBox1" runat="server" Checked='&lt;%# Bind("CanBeDeleted") %&gt;' /&gt; &lt;/EditItemTemplate&gt; &lt;ItemTemplate&gt; &lt;asp:CheckBox ID="CheckBox1" runat="server" Checked='&lt;%# Bind("CanBeDeleted") %&gt;' Enabled="false" /&gt; &lt;/ItemTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:BoundField DataField="No. of PCs" HeaderText="No. of PCs" ReadOnly="True" SortExpression="No. of PCs" /&gt; &lt;asp:TemplateField ShowHeader="False"&gt; &lt;ItemTemplate&gt; &lt;asp:LinkButton ID="LinkButton1" runat="server" CausesValidation="False" CommandName="Delete" Text="Delete"&gt;&lt;/asp:LinkButton&gt; &lt;/ItemTemplate&gt; &lt;/asp:TemplateField&gt; &lt;/Columns&gt; &lt;FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" /&gt; &lt;PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" /&gt; &lt;SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" /&gt; &lt;HeaderStyle BackColor="#4F81BD" Font-Bold="True" ForeColor="White" Height="30px" /&gt; &lt;EditRowStyle BackColor="#999999" /&gt; &lt;AlternatingRowStyle BackColor="#E9EDF4" ForeColor="#284775" /&gt; &lt;/asp:GridView&gt; &lt;asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="&lt;%$ ConnectionStrings:SumooHAgentDBConnectionString %&gt;" SelectCommand="SELECT MachineGroups.MachineGroupID, MachineGroups.MachineGroupName, MachineGroups.MachineGroupDesc, MachineGroups.TimeAdded, MachineGroups.CanBeDeleted, COUNT(Machines.MachineName) AS 'No. of PCs' FROM MachineGroups FULL OUTER JOIN Machines ON Machines.MachineGroupID = MachineGroups.MachineGroupID GROUP BY MachineGroups.MachineGroupID, MachineGroups.MachineGroupName, MachineGroups.MachineGroupDesc, MachineGroups.TimeAdded, MachineGroups.CanBeDeleted" DeleteCommand="DELETE FROM MachineGroups WHERE (MachineGroupID = @original_MachineGroupID) AND (MachineGroupName = @original_MachineGroupName) AND (MachineGroupDesc = @original_MachineGroupDesc) AND (CanBeDeleted = @original_CanBeDeleted) AND (TimeAdded = @original_TimeAdded)"&gt; &lt;DeleteParameters&gt; &lt;asp:Parameter Name="original_MachineGroupID" /&gt; &lt;asp:Parameter Name="original_MachineGroupName" /&gt; &lt;asp:Parameter Name="original_MachineGroupDesc" /&gt; &lt;asp:Parameter Name="original_CanBeDeleted" /&gt; &lt;asp:Parameter Name="original_TimeAdded" /&gt; &lt;/DeleteParameters&gt; &lt;/asp:SqlDataSource&gt; </code></pre> <p>Please suggest what to do..</p>
 

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