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.
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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
<asp:DropDownList ID="DropDownList_HP" runat="server"
AppendDataBoundItems="True" DataSourceID="SqlDataSource_HP" [code]...
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
http://msdn.microsoft.com/en-us/library/ms366709.aspx
So I changed the ListItem in the DropDownList markup to the following:
<asp:DropDownList ID="DropDownList_RefHospDV4" runat="server"
AppendDataBoundItems="True" DataSourceID="SqlDataSource_RefHosp" [code]...
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 -".
Actually i have a table with 7 columns
1) Title varchar(100)
2)Description varchar(300)
3)ProfilePicture varbinary(max)
4) Image1 varbinary (max)
5)Image2 varbinary(max)
6)Image3 varbinary(max)
7)Image4 varbinary(max)
Image1,2,3,4 are not a mandatory fields so, when i inserted, i check it if it is not there then i insert null value, Now problem is when i retrive them if there is a row contain image1,2 are image content and 3,4 are null values dataset also filling as it is in database but when i checking like
[code]....
it shows error like
Unable to cast object of type 'System.DBNull' to type 'System.Byte[]'.
i am using the following in a stored procedure.
[code]....
[Code]....Handling NULL...Field not updating when NULL?
I remember being told that you can add some syntax to the end of a statement that will do something if the field is null. Pretty vague, but I cant seem to find anything about it via google.
I definitely isnt how to set a field to be nullable. I know that.
Here is an example of what I want.
int? field1 = 0;
field1 = int.parse(string2); (where string2 is a passed value, that could be null)
I thought there was something you could put at ?? if it is a null, such as:
field1 = int.parse(string2) ??;
Or do I have to check every if every string2 is null before making that statement.
how can insert null value into integer field
View 3 RepliesIn 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
#region Save Package
protected void btnBack_Click(object sender, EventArgs e)
{
this.Response.Redirect("/?id=Promotion.PackageList");
}
[Code]....
I'm having a spot of trouble figure out how to write my linq query so that is allows a decimal field in my datatable to be null
Right now I have this:
[Code]....
But it's not working. The error I am getting is: Cannot cast DBNull.Value to type 'System.Decimal'. Please use a nullable type.so how do I get it to allow program_ar_id to be null?
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 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 am calling a Java-script function, in that i am passing the value of hidden field, that hidden field i want to use at server-side, but the value of hidden field is null.
Client Side function
function getDetails()
{
document.forms[0].HdnNode.value=tree_selected_id; //HTML Hidden Field.
str="Cmp_12";
str_array=str.split("_");
var str_array1=str_array[0];
var str_array2=str_array[1];
document.getElementById("<%=HiddenNodeId.ClientId %>").value=str_array1;
document.getElementById("<%=HiddenTreeId.ClientId %>").value=str_array2;
}
Server Side Function
Public Sub InsertNodes(ByVal NodeId As String)
Dim objErrorObj As New ErrorObj
Dim ParentID As String
ParentID = HiddenNodeParent.Value
NodeId = HiddenNodeId.Value
Dim NodeIDTree As String
NodeIDTree = HiddenTreeId.Value
End Sub
I have a form and stored procedure that inserts the data from the form. It works fine except that if a field isn't filled in it doesn't insert a NULL into sql it inserts "".
I've tried a few different ways but none seem to insert NULL, the one below still inserts "", can anyone point me in the right direction.
Here is the required part of the code, if you require more just let me know.
[code]....
So if I enter nothing into address1 field it should write NULL to screen but it always writes NOT NULL.
i want my query to return results where the field address is not empty or null
however, the query i have is still returning results where address is empty i.e. ' ' .
I have a data type mismatch while inserting into a number field in an access database using a parameterized query.I think this should be pretty simple but I am still learning a lot.
[Code]....
I have some commented out as I am working one field at a time. The working fields are textboxes and the non working ones are dropdown lists. But I think it may be the field that the list is drawing from? Not sure.
I am using a GridView Control to display multiple fileds with 0's and 1's.
I am using template fields where CheckBoxes are used.
Where exactly and how do I apply the Logic to get a checked CheckBox when field Value=1 and unchecked CheckBox when field Value=2 .Also some times to be able to write a YES where fieldValue=1 or NO where filedValue=0
Do I apply this logic using asp or C#? How?
I wanna join all the field as a new col.
but how can i ignore the empty field because i always join the field and separate by space like the following.
select (field_1+' '+field_2+' '+field_3) as new_col from TABLEA
but if the field is empty, then there is the double space
how can i ensure all the space is one space only.
I have 2 fields in my gridview one called ScriptType the other BagNo, when a user click the edit button, I would like the BagNo filed to be disabled if the ScriptType field is = "TTA" and enabled otherwise. How can I do this?..something along these lines see below..I am using VB..
[code]...
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?
My database includes a table with sever filds which are defined as (varchar(1),null), I tried using DBNull.Value, null, ' ' but cannot get a null inserted in that field of the database,
[Code]....
I have req where i have to pass null value,if value coming from db is null.Problem here is the field datatype is 'Decimal' so all the time even though value is null ,its passing as zero.How can I pass a null value to decimal field in C#.
FieldValue = (reader["Field"] ==
DBNull.Value) ?
Convert.ToDecimal(null) :
Convert.ToDecimal(reader["field"]);
What I want is ,Field value will get null value assigned not zero.
I have a date field in a typed dataset that created from database.
I get an NULL Value exception when I try to enter some null value. I am not able to set the Nullvalue property of the DateTime field in XSD to other value other than Throw Exception.
I have defined a field validator that works fine on normal behavior on a page:
<asp:RequiredFieldValidator runat="server" ErrorMessage="errroooorr" ControlToValidate="TextBoxHouseNumber" Display="Dynamic"></asp:RequiredFieldValidator>
Now if I dont insert any text in the TextBoxHouseNumber field, and push submit, the FieldValidator fires as it should. But if I now click a button that automatically fills the TextBoxHouseNumber with text from a Jquery/Ajax function, the field validator still shows. Itīs like "Hey, the user hasnt made any changes to the textbox, so I wont bother check it".
I have a aspx page with a ascx control inside an ascx control and the required field validator is not hit on the action of the page.
The issue is with the 2nd nested ascx control. The field validators in the first ascx control validate correctly, but with the ascx control inside the ascx control there are issues.
The nested ascx control is a repeater control and this may be the reason, but I am unsure.
I'm not exactly sure what question to ask, but I'll list a few below.
How do I attach the field validators up a level to the 1st ascx control?
Is it possible to put required fields into a nested ascx control?
I am hiding a TextBoxin my aspx page like this: myField.visible=false; Now I have a DropDown as well which tries to access the TextBox on IndexChange. The problem is, it cant access the hiffen TextBox and I am getting document.form[0] is Null or Not an Object. How can I solve that? Is the some check for that in JavaScript?
View 1 RepliesI'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):
<asp:Image ID="Image" runat="server" ImageUrl ='<%#Eval("UserId","Image.aspx?UserId={0}") %>'
Following is the successful code behind for the page image.aspx referred to above (page = image.aspx.vb):
[code]....
