ADO.NET :: Isnull And Nullable Int Data Type?
Dec 9, 2010I want to convert the following SQL line to LINQ :
[Code]....
Similar Messages:
DataSource Controls :: The Null Value Cannot Be Assigned To A Member With Type System.Decimal Which Is A Non-nullable Value Type
Dec 22, 2010I am making a website to store invoices so i can mail them to clients. So i got a table for clients, invoices and one with invoice products/services. When an invoice has no products/services added to them and it returns null i get the error "the null value cannot be assigned to a member with type System.Decimal which is a non-nullable value type."
I just started with linq. Before i always used mysql. Mostly i just had to call data from 1 table so forgive me if my linq query isn't really correct.
Dim invoices = From i In db.invoices _
Group Join p In db.products On i.id Equals p.invoiceId Into invoiceProducts = Group _
Select New With {i.client.naam, i.titel, (From iP In invoiceProducts Select iP.prijs).Sum}
i show the client's name, the title of the invoice and the total amount the clients will need to pay for products and services.
Databases :: Catching NULL Values Error "Cannot Cast DBNull.Value To Type 'System.Double'. Please Use A Nullable Type"
Apr 21, 2010I am LINQ querrying against a datatable. However, I am unsuccessfull with catching null values. Here is my code that is giving me the following error.
[Code]....
I am checking to see if minperc is null. However to check that it still is trying to convert the value to double. Cant figure out a way around it. Here is the error: Cannot cast DBNull.Value to type 'System.Double'. Please use a nullable type.
Use With A Reference Type Or Nullable Type
Sep 13, 2010Why following Code giving Nullable Error, it should converted to int right?int? abc=Session["test"] as int;t be used with a reference type or nullable type ('int' is a non-nullable value type)
View 9 RepliesC# - MVC 2 - Force User To Select A Value For A Non-nullable Type?
Aug 10, 2010I have (or so I think!) a simple problem.
I will greatly simplify my model to speed this along.
I have a model class lets call it item:
public class Item
{
[Required(ErrorMessage="Must indicate if product is to be tracked by serial number.")]
public bool TrackedBySerial { get; set; }
}
I have an "Add" view where I create a DropDownList like so:
<%= Html.DropDownListFor(model=>model.TrackedBySerial, new SelectList(new List<object> {null,true,false},null),"Select One") %>
<%= Html.ValidationMessageFor(model => model.TrackedBySerial) %>
My problem is that unless I create my boolean value in the model to be a nullable type, I can't force the blank default value.
If I use the Html.DropDownList() instead of DropDownListFor() , is there any way for me to use ModelState.IsValid -- or do I need to mix my own custom validation in my controller as well?
Update: So I got the functionality I was looking for, its just a bit more verbose than I'd have liked. Is there a better way to do this?
Controller:
[HttpPost]
public ActionResult Add(InventoryItem newItem)
{
try
{
//get the selected form value
string formVal = Request.Form["TrackBySerial"];
//convert to true, false, or null
bool? selectedValue = TryParseNullable.TryParseNullableBool(formVal);
//if there is no value, add an error
if (!selectedValue.HasValue).....
view:
<div class="editor-field">
<%=Html.DropDownList("TrackBySerial","- Select One- ") %>
<%=Html.ValidationMessage("TrackBySerial") %>
<%= Html.ValidationMessageFor(model => model.TrackedBySerial) %>
</div>
MVC :: Getting A Routing Error Regarding ZipCode Not Being A Non-nullable Type?
Jul 30, 2010I have a question regarding routing and an issue that I am currently having in my application. I have an action, providers/List/, which accepts two parameters, a zipCode and a page value for paging results. I have defined this route as follows in my global.asax, /providers/{zipCode}/{page}
I have created another action in this controller, Dashboard, which does not expect any parameters, so I am assuming that the route would ultimately be /providers/dashboard, if I am not mistaken. What is happening is that for some reason I am getting a routing error regarding zipCode not being a non-nullable type. It makes me think that the first action's route is what is getting hit instead of going to the dashboard action. I am sure that it has something to do with the route entry that I have made in my global.asax file.
MVC :: The Null Value Cannot Be Assigned To A Member With Type System.Int32 Which Is A Non-nullable Value?
Dec 26, 2010When i click on the page that represents a controller the following error was displayed:-
"The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type"
On this link of code
var articleapproval = articletyperepository.FindAllArticlesRequireMyApproval().ToList();
while the FindAllArticlesRequireMyApproval execute the following LINQ statement :-
var articleapproval= articletyperepository.FindAllArticlesRequireMyApproval().ToList();
where this methods calls the following LINQ statement:-
ADO.NET :: The Null Value Cannot Be Assigned To A Member With Type System.Int32 Which Is A Non-nullable Valu...
Nov 17, 2010My code:
[Code]....
If the value is null writes out that error.How to check if the value is null? And if the value is null, I want to store + 1
How To Write Extension Methods For Both Nullable And Not Nullable
Nov 10, 2010I've written the following Extension Method
<Extension()>
Public Function ToUtcIso8601(ByVal dt As Date) As String
Return String.Format("{0:s}Z", dt)
End Function
But I also need a Nullable version of the same method... how exactly do I do this?
This is what I was thinking, but I'm not sure if this is the right way
[code]....
MVC :: Nullable DateTime And DatePicker - Dictionary Requires A Non-null Model Item Of Type 'System.DateTime
Apr 1, 2011I have a problem:
I've created usual Controller and View(Edit view) for editing my Entity (EntityFramework)
Here is view example:
<div class="editor-field">
@Html.EditorFor(model => model.BirthDate)
@Html.ValidationMessageFor(model => model.BirthDate)
</div>
BirthDate is Nullable<DateTime>
but during loading my View I get this exception
The model item passed into the dictionary is null, but this dictionary requires a non-null model item of type 'System.DateTime'.
That's because of BirthDate is null in database but it is nullable and I expect that it just leaves the filed empty.
And I have Shared EditorTemplate:
@model System.Nullable<System.DateTime>
@if (Model.HasValue)
Using ISNULL With DATEDIFF Gives Wrong Number Of Arguments Error?
Jan 31, 2011I have to believe that I'm just missing something silly on this one. It SHOULD work... but alas, it is not. Here is my code:
SELECT s.[id], s.[familyid], s.[lastname], s.[firstname], s.[middlename], s.[suffix], s.[nickname], s.[dob], fix(datediff(d, isnull(s.DOB, Now()), NOW()) / 365) as AGE, s.[allergies], s.[notes], s.[photographsOK], s.[school], f.[city], f.[state] FROM [Students] s, [families] f, [employee] e where s.[familyid] = f.[id] and f.[franchise] = e.[franchisename] and e.[username] = @Username order by f.[lastname]"
This was working fine before I put the "IsNull"handler in the datediff function to handle problems with null dates. Now I get the following error when I try to run it.Wrong number of arguments used with function in query expression 'fix(datediff('d', isnull(s.[DOB], now()), NOW()) / 365)'. I even tried using just the ISNULL(s.[DOB], NOW()) without the Datediff and get the same error.
Forms Data Controls :: Map Nullable Foreign Key To Dropdown List?
Apr 12, 2010I have dropdownlist that maps from a SQL foreign key, which can be NULL.
Currently, I've added a "Please select..." to the top of my dropdown list and assigned it a value of 0.
I know how to map from the drop down list to SQL using a CASE statement in my UpdateCommand.
But how to I map from the SELECT statement to my dropdownlist? If this foreign key contains null I get "Item not in Dropdown list". I'd like to show "Please Select..." as the dropdownlist item if the SQL item contains NULL. I saw something online that says to use the value '''' for 'Please select...', but I don't think it's right, plus it doesn't work.
Do I have to do something in my SELECT statement or do I have to do something on DDL.Databind?
LINQ Group By And Compare Date Error Message - The Conversion Of A Char Data Type To A Datetime Data Type
Jan 27, 2011I have the following:
[code]....
I keep getting this error:
Message = "The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value."
What i'm trying to do is group by ContentObjectId and then get StartDate that is greater than today.
I'm using entity framwork and MS SQL2008
Forms Data Controls :: Conversion From Type 'TextBox' To Type 'String' Is Not Valid?
Sep 6, 2010I have a FormView that allows a user to register for a company event. I want to do a couple of things with this form.
1. I need to write this data to a MS SQL database
2. I need to send an email confirmation of their registration to their email.
I know how to do both of these things, but i am having trouble doing both at the same time.
It would be nice if I could do it in one click, but I coded it into two pages to try to help simplify it.
The first page allows the user to input their information into a formview and when they click the submit button, it places those answers into session variables:
[Code]....
[Code]....
The Second page confirms the users information by taking those session variables and placing them into labels:
[Code]....
[Code]....
However, after I place information into the formview on the first page, it throws up this error:
"Conversion from type 'TextBox' to type 'String' is not valid".
DataSource Controls :: The Given Value Of Type String From The Data Source Cannot Be Converted To Type Datetime
May 19, 2010I have this error "The given value of type String from the data source cannot be converted to type datetime of the specified target column." when I used sqlbulkcopy to do the transaction
Here is my code:
[code]....
C# - Unable To Cast Object Of Type 'Transaction_Time' To Type 'System.Data.DataSet'?
Dec 17, 2010I have built a dataset named Transaction_Time.I called it on Page_Load
Transaction_Time tranTme = new Transaction_Time();
put it in the session.
Session["Transaction"] = tranTme;
Then I call that session and cast to dataset.
DataSet dstTranTime = (DataSet)Session["Transaction"];
I got the following error.Unable to cast object of type 'Transaction_Time' to type 'System.Data.DataSet'.
[InvalidCastException: Unable to cast object of type 'Transaction_Time' to type 'System.Data.DataSet'.]
Transaction_Time.Page_Load(Object sender, EventArgs e) in c:InetpubwwwrootWilliam29_11_2010Transaction_Time.aspx.cs:47
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +50
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627
It is OK for some other pages. But for some page, it doesn't.
Possible To Assign A Data Type To An Anonymous Type's Members In A Linq Query?
May 5, 2010If I have a linq query that creates the anonymous type below:
select new
{
lf.id,
lf.name
lf.desc,
plf.childId
};
Is it possible to assign a specific type to one of the members? Specifically I would like to make lf.id a null-able int rather than an int...
Forms Data Controls :: ERROR - Conversion From Type DBNull To Type String Is Not Valid?
Jan 13, 2010I have a gridview which I'm trying to get the display of phonenumbers listed in a certain display format; (xxx) xxx-xxxx.If I have the code such as this, it displays the unformatted phone number and (000) 000-0000 for the null items.
[Code]....
Forms Data Controls :: Generate Three Type Of Multi application Form For Each Passenger Type ?
Oct 23, 2010i 'm working on AIRLINE RESERVATION PORTAL and it's ok how to do this ?
the user most select the number of passenger and passenger's type (Adult,Child,Infant) for example he select 2-adult,3child,1-Infant
and go next , in the next page i have to generate three type of multi application form for each passenger type
2 adult application form
3 Child application form
1 Infant application form
depend on last selected vales , to save the applications in database
Forms Data Controls :: Gridview Rowdatabound Best Way To Add If Conditions For Item Tempate Type And Edititemtemplate Type
Apr 2, 2010I am having problem with rowdatabound, want to add if conditions intact, i am using teh following two if conditions and they don't look right. i found them on google.
If e.Row.RowState = DataControlRowState.Normal Or e.Row.RowState = DataControlRowState.Alternate Then end if
If e.Row.RowState = DataControlRowState.Edit Or e.Row.RowState = 5 Then end if
With datagrids i use these and they work excellent:
If e.Item.ItemType = System.Web.UI.WebControls.ListItemType.Item OrElse e.Item.ItemType = System.Web.UI.WebControls.ListItemType.AlternatingItem Then
end if.....
Forms Data Controls :: No Mapping Exists From Object Type System.String[] To A Known Managed Provider Native Type?
Dec 1, 2010I'm trying to pass email addresses from an array to a stored procedure, then display the results in my gridview. I get the following error:No mapping exists from object type System.String[] to a known managed provider native type.On this line: Dim DR As SqlDataReader = MyCommand.ExecuteReader
[Code]....
MVC :: Selectlists And Nullable Properties
Jan 25, 2010I have a ASP.NET MVC view that displays a single ServiceProvider object. In this view there is a selectlist that lists one or more ServiceProviderGroup objects and uses the Id property for the value and the Name property for the text. In this list I also show a entry with a value of -1 and text of "No Provider". When the Edit[Post] method is called the Id value from the select list maps to a nullable property (GroupId) on a ServiceProvider object. When a value other the -1 is selected from the list it works as expected. But, when the value is -1, I want a NULL reference to be applied to the GroupId property during the UpdateModel call. Within the Edit method, prior to calling UpdateModel, I have tried replacing the entry within the Controller.ValueProvider with a null reference and adding a ValueProviderResult which contains a null reference, but the UpdateModel always has an issue (InvalidOperationException).
View 3 RepliesBinding A Nullable Int To An Asp:TextBox?
Mar 25, 2010I have a property int? MyProperty as a member in my datasource (ObjectDataSource). Can I bind this to a TextBox, like
<asp:TextBox ID="MyTextBox" runat="server" Text='<%# Bind("MyProperty") %>' />
Basically I want to get a null value displayed as blank "" in the TextBox, and a number as a number. If the TextBox is blank MyProperty shall be set to null. If the TextBox has a number in it, MyProperty should be set to this number.If I try it I get an exception: "Blank is not a valid Int32".
But how can I do that? How to work with nullable properties and Bind?
MVC :: EF Model With Nullable Fields?
Oct 27, 2010I have a problem with passing a model to a controllerIn my controller I have a HttpPost function that gets a EF model.The problem is that the form does not contains all properties of the EF model.When the function is called that gets this EF model, I get error messge of fields that are not nullable in the EF model.That's because the fields are not in the form, so the not nullable properties gets no value.
View 5 RepliesC# - Comparing Nullable DateTime's In VB.net?
Nov 17, 2010I am a c#/asp.net developer and I am having to work on a VB/asp.net. I started out with VB.NET but after years away from it I'm getting confused with the syntax.
I have two variables
Dim originalDate as DateTime?
Dim newDate as DateTime?
Both nullable datetimes, originalDate is a nullable date I am getting from the database and newDate time is set in code, I need to compare them, they can either both have dates, neither have dates or one have and one not.
I have a bit of code as follows:
if origEndDate = origEndDate then
When both origEndDate and origEndDate are "nothing" this statement is false (well when I run it in the watch window it comes back as nothing)!
I don't understand why this is the case because I was under the impression doing an "=" compares the two values and as they are the same surely it should be true?
What syntax should I be using as in C# I can do the above as so:
if (origEndDate == origEndDate) { }
and it will come back as true.