error when changing sort key in gridview to a non-numeric value

VB.NET on VS2008 with MS SQL2005 backend

I have a gridview which is devoid of any columns as I am using a single template field for each row.  The user can select a sort key from a dropdown list (outside of the gridview) and once selected the gridview will re-sort itself based on the selection. (see code - using a control parameter of the dropdownlist)

This works well for numeric values but as soon as I try to sort using a nchar(50) datatable field I receive an error as folows

"Error Converting Data Type Varchar To Bigint."

So my problem is when I try to sort on the Domain field of the example supplied in code. Sorting on the other 2 fields works perfectly.
<asp:SqlDataSource ID="SqlDataSource_ContactHyperlink" runat="server" ConnectionString="<%$ ConnectionStrings:conn_db1 %>"
                                            ProviderName="System.Data.SqlClient" SelectCommand="SELECT IndexID, OrderID, 
                                            hyperlink_url, DomainName, hyperlink_memo, origin_UserName, origin_UserID, origin_Visibility, 
                                            origin_dateTime, starRating FROM tbl_bookmarks
                                            WHERE origin_UserID = @curUserID
                                            ORDER BY CASE @SortBy
                                            WHEN 'IndexID' THEN IndexID 
                                            WHEN 'starRating' THEN starRating
                                            WHEN 'domain' THEN DomainName
                                            END">
                                            <SelectParameters>
                                                <asp:SessionParameter Name="curUserID" SessionField="UserGUID" Type="String" />
                                                <asp:ControlParameter ControlID="DropDownList_sortOrder" Name="SortBy" PropertyName="SelectedValue"
                                                    Type="String" />
                                            </SelectParameters>
                                        </asp:SqlDataSource>

Open in new window

JOHNFROGAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
Hope this helps:

Since your DomainName was character, it creates the problem for other WHEN Clauses in your CASE statement.
SELECT IndexID, OrderID, 
hyperlink_url, DomainName, hyperlink_memo, origin_UserName, origin_UserID, origin_Visibility, 
origin_dateTime, starRating FROM tbl_bookmarks
WHERE origin_UserID = @curUserID
ORDER BY CASE @SortBy
WHEN 'IndexID' THEN cast(IndexID AS varchar(1000))
WHEN 'starRating' THEN cast(starRating AS varchar(1000))
WHEN 'domain' THEN DomainName
END

Open in new window

0
Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
Or check whether you pass varchar values instead of bigint for @curUserID
0
JOHNFROGAuthor Commented:
That confuses me as what you are doing is converting all the other fields to character based fields and leaving the problematic one alone. Will give it a try and see what happens though. The curUserID is a GUID so it definately isnt bigint either.

Remember this works for all sorts except the domainname field which is nchar(50)

Have been playing with using RTrim on the DomainName field but cant get the syntax right. Is this perhaps the solution or am i barking up the wrong tree??
0
Determine the Perfect Price for Your IT Services

Do you wonder if your IT business is truly profitable or if you should raise your prices? Learn how to calculate your overhead burden with our free interactive tool and use it to determine the right price for your IT services. Download your free eBook now!

Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
Let me explain clearly.

In a CASE statement, the THEN Clause that is your output should be in same datatype for all WHEN clauses.

You have IndexID and starRating as integers/ bigint and DomainName as Varchar.
Obviously to resolve out this issue, you have to convert it into a common datatype either Varchar / bigint.
Conversion from bigint to varchar is possible whereas varchar to bigint is not possible.

And hence I converted all fields to varchar which should work out fine.

Hope this clarifies.
0
JOHNFROGAuthor Commented:
Thanks I didnt know that. Got my stripes on MS Access so that will probably explain it.

While we are on the subject can you tell me if it creates extra overhead if I was to create multiple SqlDataSources on my page and simply toggled between them upon changing of the dropdown list?
0
Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
>> can you tell me if it creates extra overhead if I was to create multiple SqlDataSources on my page and simply toggled between them upon changing of the dropdown list?

As far as you manage the connections properly by opening and closing as required, there is no overhead on it.
But if you have multiple things opened and not properly closed then it might bring the system down by not allowing to open new connections and connection resource related issues.

Hope that query too worked out.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
JOHNFROGAuthor Commented:
works brilliantly - next time I will be less critical of answers that seem a bit strange.

Will be posting another shortly on the same block of code re getting the ascending descending to work. Currently am toggling between 2 identical SqlDataSources to achieve asc and desc outcomes.

0
JOHNFROGAuthor Commented:
flawless !
0
Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
Thanks..
And glad to help you out now and in future too..
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft SQL Server

From novice to tech pro — start learning today.