Forms Data Controls :: Checking IDataReader For Valid Data?
Aug 3, 2010
I'm populating a DataList using the IDataReader object and it works fine it the reader contains data. If the data is not present it displays nothing. I want to capture that situation and insert a verbiage such as "No data" or something like that. I've tried to test the datareader for various conditions such as Null, String.Empty, or plain " " but nothing worked. Is there a way to make this happen? Below is my code sample for your review.EJM.Note: It has to be done programatically as I'm building this for a web part.
I've always been a bit unsure how to check for the existance of properly referenced table data.
In my situation I have various tables related to each other in many-to-one relationships where the "1" side can be deleted without the reference fields on the "many" side being updated (nulled).
I have FK relationships set up in my MS SQL server database but have turned off the FK constraint enforcement (and cascading update/delete) so that I can delete records from the "1" side but leave the keys for those deleted records in the records on the "many" side. This is something I really need to do for my web app design.
I had a web application that was binding a IDataReader to a repeater control. I converted the project from 3.5(2.0) to 4.0 and then I received the error:
An invalid data source is being used for rptData. A valid data source must implement either IListSource or IEnumerable.
So, I used a datatable instead and the binding worked. So it seems that they have removed this functionality with .NET 4.0.
I have a sign up page in my website where the user needs to enter his email id.Now i want to check whether the email id entered by the user actually exists or not...
I have an Infragistics WebDataGrid on a user control. I add that user control programmatically to an UpdatePanel on a Content Form. Everything works great. I get data in the grid just fine. However, when I go to click any of the grid functions (Sort, Filter, Page, etc.) it throws a Sys.ArgumentException in one of the ScriptResource.axd dynamic files.
Here is the error:
"Microsoft JScript runtime error: Sys.ArgumentException: Cannot deserialize. The data does not correspond to valid JSON. Parameter name: data"
It stops in the following function:
[Code]....
I read about other people having this issue and they said it was due to dates or due to double quotes ("") being in strings? I am binding this datagrid to an Entity Data Framework object query like this.
I've added some validation to a text box which works, only the code behind on the image button executes even if the validation shows a problem. I need some way of testing the validation and blocking the code behind from running. He's my code:
how to check if a particular data in the database already, for example, i want to check if a username already exist in database, then the user cant choose that username.
I am using seperate buttons to control whether edit and delete row linkbuttons are enabled or not on the GV. When I click a buton to enable the edit linkbuttons on the GV and then click a linkbutton for a row that puts it in edit mode. Then if the Delete button is clicked I have code that disables the edit linkbutton and enables the Delete linkbuttons. But, if there is a row in edit mode and the delete button is clicked, the edit linkbuttons disappear and the delete buttons appear (as expected) but the row that was in edit mode does not have a delete linkbutton in it and the row is still in edit mode with no update/cancel buttons. When the delete button is clicked, if there is a row in edit mode, I need to cancel any edit modes in any row.
I'm using C# and SQL Server. I have one gridview which contain 3 columns "ID, COMPLETED (either yes or no), BY (adminID that completed)" and adminID can be null.
If user selected "yes" in COMPLETED column then how can I make sure that adminID in BY column is NOT empty or adminID entered is EXIST in database.
I've been pickling my brain trying to do this for a couple of days but to no avail. I have the following in "FormView1" which I'm just using in insert mode:
I'd like the contents (i.e. whatever the user wants to insert) to be passed to a method where it will be checked against any existing values in the database.
I have some controls on the asp.net page that can be required on certain senario and can be not required on others.
So we enable/disable them dinamaically depending on the current transactions.
Now I am thinking of a way where I can check the required field by Javascript on the click event of save button. Remember control not be required at all time.
I am using a DetailsView control to allow for updating a user record. Is there a way to check if the values are actually updated/changed when the update link is clicked. I know there are users, who would click the update button rather than the "Canel" even if there are no changes to the record. So, how do I check if any value has been updated when the update link is clicked. The DetailsView uses a SqlDataSource to populate the DetailsView.
I need to check for duplicate records before inserting them into the SQL database.Thus I have the following codes:
For count = 0 To GridView1.Rows.Count If (GridView1.Rows(count).DataItem("Student Name").Equals(dtDataTable.Rows(count).Item("Student ID"))) Then lblMsg.Text = "Records Existed" End If
but there are error message. "Object variable or With block variable not set."
i have code to update multiple rows in a gridview. What I want is that if the row value is = 1 in the database then the row is checked otherwise it's not. I've put some pseudo code in below to illustrate what I want to achieve.
I having problem on the checking duplication entry on grid view. The situation is like this:
When i click Submit Button, The function will make a checking into mysql. If the data already exist then the submition of data will not being process. The error that i got here is, Both already exist and not exist data not being process. this is my checking coding
I have a formview that I open to the edit template, some textboxes are not available and some are populated by dropdown lists, and the update function works fine.
As soon as I add some logic to the code behind page for the update control, the UPDATE link on the formview stops updating my DB.
There is select and update SQLs in sqldatasource and checkbox in formview which is 2way databinded to an sqlserver bit field type.
it always gives same error
Specified cast is not valid
I excpect nobody posts me an "eval" solution.because update is a need for checkboxes which are attached to a bit field.
a ready-to-use small sample project with DB I attached HERE
Specified cast is not valid.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidCastException: Specified cast is not valid.
bolded part for extracting date in a label( lblRequestDate). is it ok by point of view security (I never get an error although the data may be complex)
