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Gridview RowUpdating Exception Handling

abenage
abenage asked
on
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Last Modified: 2013-11-11
I am attempting to update an SQL 2005 table from a gridview.  The table has a unique index on two fields, PersonID and EmailTypeID.

I can update a record successfully if the record is indeed unique:

PersonID     EmailTypeID
123             1
123             2
123             3

the record is committed to the DB and all is well.

If I attempt to update and violate the unique index such as:
PersonID     EmailTypeID
123             1
123             2
123             2

I get no response in the web page.  The update simply does not happen, but there is no indication on the page that there is a problem.

If I run Query Analyzer and run the generated SQL captured from Profiler, I get the obvious:
 "Cannot insert duplicate key row"

I tried to use:
    Protected Sub grdEmails_RowUpdating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewUpdateEventArgs) Handles grdEmails.RowUpdating

    End Sub

but I can't seem to expose any exception class from e.

I am using a LinqDataSource... and I only have two properties in my codebehind

How can I trap the exception?

Thanks,
Aaron

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:GridView ID="grdEmails" runat="server" AutoGenerateColumns="False" DataSourceID="ldsPersonEmails" 
    DataKeyNames="EmailRecordID" OnRowUpdating="UpdateEmails">
    <Columns>
        <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" EditText="edit" DeleteText="delete" />
        <asp:TemplateField HeaderText="Email">
            <EditItemTemplate>
                <asp:TextBox ID="txtEditEmailAddress" runat="server" Text='<%# Bind("EmailAddress")%>' ></asp:TextBox>
            </EditItemTemplate>
            <FooterTemplate>
                Add
                <asp:TextBox ID="txtNewEmailAddress1" runat="server"></asp:TextBox>
            </FooterTemplate>
            <ItemTemplate>
                <asp:HyperLink ID="hlkEmailAddress" runat="server" NavigateUrl='<%# Eval("EmailAddress", "mailto:{0}") %>'
                    Text='<%# Eval("EmailAddress") %>'>
                </asp:HyperLink>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Type">
            <FooterTemplate>
                <asp:DropDownList ID="ddlEmailTypes1" DataSourceID="ldsEmailTypes" DataValueField="EmailTypeID"
                    DataTextField="EmailDescription"  runat="server">
                </asp:DropDownList>
            </FooterTemplate>
            <ItemTemplate>
                <%#Eval("email_type.EmailDescription")%>
            </ItemTemplate>
            <EditItemTemplate>
                <asp:DropDownList ID="ddlEmailTypes2" DataSourceID="ldsEmailTypes" DataValueField="EmailTypeID"
                    DataTextField="EmailDescription" SelectedValue='<%#Bind("EmailTypeID")%>' runat="server">
                </asp:DropDownList>
            </EditItemTemplate>
        </asp:TemplateField>
    </Columns>
    <EmptyDataTemplate>
        No email addresses on file.<br />
        <br />
        Add a new email address:<br />
        <asp:TextBox ID="txtNewEmailAddress2" runat="server"></asp:TextBox>
        <asp:DropDownList ID="ddlEmailTypes3" DataSourceID="ldsEmailTypes" DataValueField="EmailTypeID"
                    DataTextField="EmailDescription"  runat="server">
        </asp:DropDownList>
        <asp:LinkButton ID="lnkAddNewEmailEmptyData" runat="server">Add</asp:LinkButton>
    </EmptyDataTemplate>
</asp:GridView>
<asp:LinqDataSource ID="ldsPersonEmails" runat="server" ContextTypeName="VBCODE.jhadbDataClassesDataContext"
    TableName="person_emails" Where="PersonID == @PersonID" EnableDelete="True" EnableInsert="True"
    EnableUpdate="True">
    <WhereParameters>
        <asp:QueryStringParameter Name="PersonID" QueryStringField="PersonID" Type="Int32" />
    </WhereParameters>
</asp:LinqDataSource>
<asp:LinqDataSource ID="ldsEmailTypes" ContextTypeName="VBCODE.jhadbDataClassesDataContext"
    TableName="email_types" runat="server">
</asp:LinqDataSource>
</ContentTemplate>
</asp:UpdatePanel>

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Hi

Did you get any exception like the below
Could not find a row that matches the given keys in the original values stored in ViewState.  Ensure that the 'keys' dictionary contains unique key values that correspond to a row returned from the previous Select operation.

Author

Commented:
I think I have ran into that problem and I needed to make sure there was a unique column on the database table.  For example, I was using the PersonID and EmailTypeID columns for the primary key.  What I had to do was create a EmailRecordID column, type INT, Identity True and set that as the Primary key.  I then used the other two columns to create a unique index.  Then, in my gridview, I set the DataKeyNames to the new EmailRecordID column.  Does this help you?
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Author

Commented:
I got it with LinqDataSource.OnUpdating.  Thanks!

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