Web Forms :: Adding Record With Null Date Field With LinqToSql
May 14, 2010
Dim newMem As New Subscription With { _
.First = txtName.Text, _
.Email = txtEmail.Text, _
.dateLastEmail = "1/1/1980", _
.subDate = Now}
dbp.Subscriptions.InsertOnSubmit(newMem)
dbp.SubmitChanges()
The table contains a field called conDate that is nullable, and in this case I want it to remain null. It will get a date value later, when a confirmation is received. If I add .conDate = "1/1/1980", _ I can successfully add the record, but without that line I get System.InvalidOperationException: Nullable object must have a value. I tried this:
Dim DateConfirm As System.Nullable(Of DateTime) = Nothing and adding
.conDate = DateConfirm, _ but that didn't help either. How can I add a record without giving a date to a field I want to remain null?
In the below code when I remove the optional end date and click save it should just take the value as blank, but it doesn't
when I remove the date and click save it saves but still shows the same date as before...when I make it to null it should remain null...how do i do that
I have a form that contains a text box called "MyDate" in which the user enters a date. I have a table that contains records of which one of the fields in the record is a date field named "DateAvailable" (type is "datetime"). I want to compare the data in the text box to the "DateAvailable" field in record. How do I define my text box as a "datetime" field.
I'm using MVC 2 with some Models from a LinqToSql project that I built. I see that when I post back to a Controller Action after editing a form that has a DateTime field from the Model, the MVC Html.ValidationMessageFor() helper will nicely display an error beside the Date text box. This seems to happen automatically when the you test ModelState.IsValid() in the Controller Action, as if the MVC model binding automatically knows that the DateTime field cannot be empty.
My question is... I have some other string fields in these LinqToSql generated classes that are Not-Nullable (marked as Not Nullable in Sql Server which passes thourgh to the LinqToSql generated classes), so why doesn't Mr. MVC pick up on those as well and display a "Required" message in the ValidationMessageFor() placeholders I have added for those fields?
Sure, I have successfully added the MetadataType(typeof<t>) buddy classes to cover these Non-nullable string fields, but it sure does seem redundant to add all this metadata in buddy classes when the LinqToSql generated classes already contain enough info that MVC could sniff out. It MVC validation works with DateTime automatically, why not these Not-nullable fields too?
I have a DetailsView on the page and I have made one of the fields a TemplateField. In the EditItemTemplate and InsertItemTemplate I have a DropdownList that is databound to a table in my Sql Server database. I wanted to add an initial value to the DropdownList namely "- select -" .
I set the AppendDataBoundItems property to true and added the initial value as a ListItem.Markup of the DropdownList
This works fine for new input. The problem is however that the database already has records that were entered through a Windows Application and many of these records has a null value in this field and exceptions are thrown when I tried to open these records and the system tried to set the SelectedValue of the DropdownList.After some more searching I found this help
This now solved the problem of opening a record where the value is null in the database, BUT now the RequiredFieldValidator is not validating anymore to make sure that a databound item is selected for this field and not the initial value "- select -". So basically now it is not checking anymore to see if valid input has been entered for the DropDownList and it accepts "- select -" thus it acts as if the field is not a required field anymore.
In short what is required is that I want to make sure that the user enters a valid selection in the DropDownList, but it must also cater for old records that do not have this field entered yet so that those old records can be opened in the DetailsView .Opening Old records (with null in that field):When these old records are opened in the DetailsView the DropDownlist should show "- select -" when the value in the database is null.
Saving records (old or new records):When saving the record in Insert mode or Update mode the RequiredFieldValidator should show that a valid input is not selected if the DropDownList is still on "- select -".
How to get the date at which a record is created in SQL?..i.e, if i add a record to a database table db1 at 8/10/2010 11:30, I want to get the datetime, i.e 8/10/2010 11:30..;.Also let me know how to compare datetime values..
if(8/10/2010 11:30 >8/10/2010 10:30) will work or not?
I have a page with a FormView on it. The page is strictly for adding records to a Table. I have the FormView bound to an EntityDataSource and everything works greate except for one thing.
I want to initialize a date field in the FormView to today's date. So, in my page_load event I have:
if (!Page.IsPostBack) { //Initialize SetupDate to today. TextBox setupdate = (TextBox)fvJob.FindControl("txtSetupDate"); setupdate.Text = DateTime.Now.ToShortDateString(); }
The first time this page loads, the txtSetupDate field is initialized.
Although, and subsequent loads of the page doesn't initialize the Text Box. I step through the code in the debugger and I can see that the code is executig, but something (the FormView bind?) is "clearing" the Text Box.
I have a databound gridview that displays basic customer information. I have added a template field to the gridview, but I am having trouble with the coding for the RowDataBound event. I need to take the sum of all payments made by the customer in each row and store it in a variable for further calculation. Also, I need to take an integer value (say 30, representing 30 days) and add it to a date, and return a date.
I am filtering dataview using my Date Column but the result is not proper because the Field value also stores time, so I want to convert this Date Field to only Date during Filter. How can I achieve this? Here is my code. And the actual value I am getting in the Dataset Field "CreationDate" is a DateTime field which is like
In Microsoft Access Database Form, I have a series of five fields. I would like to set up a field that is equal to the first field unless that field is null or 0. Then I want the field to be equal to the second field unless that field is null or 0, continuing the same way through the five fields. Being a newb, I have no idea how.
here is my code for selectiong some records from db table
string strSql = "select * from mtblNBD where SentTo=@SentTo and InternalStatus Is NULL order by DeadLine desc"; SqlCommand com = new SqlCommand(strSql, con); com.Parameters.Add("@SentTo", SqlDbType.NVarChar, 50).Value = (string)Session["uname"];
here I am using parameters for SenTo field but not for NULL so it is ok... or should I use parameters for this field where value is NULL , if yes then how can I use parameter for this
I am using IIS 7 and have URL rewrite turned on for a friendly URL.
The problem is that in side that pages repeater (right under the captcha) when I click on the images in there the page redirects to /null/ which then throws a 404 error. I have turned off url rewrite and removed all rules and that didnt solve the problem so I dont think its related to that.
I have also noticed that in my master page if I use <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
then the client side ajax fails to load, sys becomes undefined and that may be the problem here
I'm at a loss, this is the first time I have seen these problems occur.
I have a column in my database which contains null value. Now after retrieving value from database i want to store that value in my txtbox. I am getting
[DBTableFieldIsNullException: Field 'Title' is NULL] exception.
I have a GridView and DetailsView on the same page. If the GridView has data, I can Select a row and it brings up the DetailsView from which I can edit that record or click NEW to create a new record. Without a record to Edit, the New link and the DetailsView control is not visible. What is considered best practices for Inserting the 1st record using a same page Gridview / DetailsView combination?
I have one text box for accepting date. I want to store date column in database is null when the text box value is null and how to bind the this null value to text box when i retrieve.
I'm looking to discover a way to add the current date to the navigation urls in my tree nodes. For example, I want only get the articles from a database that are today's date....http://localhost.../Articles.aspx?CatID=1&PublicationDate=CurrentDate.
how you can do that, could you please let me know. I was trying to create a string and add it to the url, amoung other things but it doesn't seem to work.
I'm having trouble accomplishing the above. Below is all the mark up and code. I'm not getting error messages, but the validate image function is not working (fileupload portion is working ok).
In my attempt below---not sure if it's the simplest or best validation approach anyway---the "UserId" parameter appears during rendering to be empty---but in most methods I have it successfully containing or referring to the logged-in user's identification.
Following is the control that refers to the image field (page = advertisement.aspx):
How should i insert null values into a database. I have textbox1 and the textbox2 will convert the value out of textbox1, when i the time i click save and the textbox1 is empty i got an error, "Conversion from string "" to type 'Date' is not valid." i just want to insert null value if the textbox is empty.
