Losing database connections with dropdown menus

Posted on 2007-10-01
Medium Priority
Last Modified: 2013-11-26
I created an vb.net aspx page with three dropdown menus. All three dropdown menus are connected to a table in SQL. When the page is load dropdown #1 is populated with two database selections to choose from. Depending on what database you select dropdown #2 and #3 will be populated with different data. The problem, I'm having is when the page is loaded and select an item in dropdown menu #2 or/and #3 and select the submit button, I get an error message like so:

Exception Details: System.Data.SqlClient.SqlException: INSERT statement conflicted with COLUMN FOREIGN KEY constraint 'User_FK00'. The conflict occurred in database 'OMNIVISOR_PLUS_HCMB', table 'PatientGroup', column 'PatientGroupID'. Cannot insert the value NULL into column 'UserID', table 'OMNIVISOR_PLUS_HCMB.dbo.Professional'; column does not allow nulls. INSERT fails. The statement has been terminated. The statement has been terminated.

After doing it serveral time, I figured out that when the page is loaded , the items  in the dropdowns are connected to the SQL database. But once I select another items from the dropdowns, I lose connections to the SQL database. How can I prevent this from happening. I attempted to use Page.IsPostBack but it doesn't seem the fix the problem.

Any ideas? Help!
Question by:redouard
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LVL 14

Expert Comment

ID: 19992118
This looks like a completely different issue.  It looks like you are trying to insert a record into a table that is missing the required UserID field.  Unless one of the dropdown contains the UserID, the dropdowns are not likely the problem.

Author Comment

ID: 19992187
I've tested it and can reproduce the problem at will. It seems that when I called the page and select the database, it automatically populate the dropdown menus with the first records in the tables. The insert works at this point. The insert fails when I change the records to another record (or item) selected in the tables from dropdown menus #2 or/and #3.  I think I'm losing the the data bind when another item is selected after the initial page load
LVL 14

Expert Comment

ID: 19992226
OK, I see.

So what you are doing is loading the drop downs on initial load of the page and re-loading #2 and #3 when something changes in #1 or #2.  Is this correct?


Author Comment

ID: 19992236
Yes that's what I'm doing. Make sense?
LVL 14

Accepted Solution

NBSO_ISS earned 375 total points
ID: 19992280
Seems to me that what you need to do is have 2 seperate statements for loading your drop-down menus.

You will have to do use the Page.IsPostBack statement

If Page.IsPostBack then               'something on the page has caused a postback

'********************RELOAD #2 and #3 here********************

'** do a Request.Form("Name Of Dropdown") each dropdown that has been re-filled and set that value in the dropdown********

else                                               ' first time load    
' ******************** DO INITIAL LOAD HERE**************
end if

Try that and let me know how it goes.

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