The C# code below:
int? i;
i = (true ? null : 0);
gives me the error:
Type of conditional expression cannot be determined because there is no implicit conversion between '<null>' and 'int' Shouldn't this be valid?
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.
Can anyone reliably get the EDS to save a nullable column to the databse as a "null" when bound to any of the controls such as "FormView"?I have tried using several different UpdateParameters (Session, ControlParamater, Parameter, etc). I have tried setting "ConvertEmptyStringToNull" to true and leaving the property off entirely. Nothing works. On my "Inserts" it works fine.(I have made sure the column is set to nullable = true in the Entity Designer.....)
View 7 RepliesMy designer.cs file of all the SQL tables is generated by LINQ-TO-SQL. The class and attribute in question is like this.
[global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.Transfers")]
public
partial
class
Transfer :INotifyPropertyChanging,[code]...
I need to assign a null to the attribute so that the value 0 does not get save to the database.
Got a nullable datetime member on my viewmodel.the moment it hit my controller action, the viewmodel's modelstate allready are invalid (because the member is null).Forgot...how that works? (using MVC2)Basically my viewmodel have a social security number, passport number and passport expiracy date.If the ssn is entered, I want to ignore the two passport related fields, so I made the expiracy date member nullable.
Like all other viewmodels in this app, each model have it's own validation function that will do validation, and in there I add an error that the date is required or not valid (if using passport number). mvc itself should not care about the date at all.I dont want to give the date a default value, because then the date will show when the form loads, and it must be an empty field (unless I already got a date of course.
I have to change the username column in my database to nullable, which means everywhere in my code, I now have to check username.HasValue and change references to username to username.Value. Is there anything I can do to avoid having to change all the references to username to username.Value?
View 1 Replies[System.Web.Script.Services.ScriptService]
public class Quotes : System.Web.Services.WebService
{
ebMethod]
public void Calculate(int param1, int? param2)
When 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:-
My 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
I'm trying to bind a nullable bit column, which at the moment is mostly null, but I need to somehow convert the null to a 'false' on runtime because it doesn't bind to a checkbox if it's null. But, I am currently unable to change the default value and update all records accordingly - is there a way to do this in runtime?
View 2 RepliesI am having a problem with the Client Validation not firing when I have marked a nullable DateTime field as [Required] and the value of the field is null. (It is actually stopping ALL client validation on the page working - not just the DateTime field).
Interestingly enough, once a post back has been done and the error picked up on the server, the client validation starts working.
Also if you set the date to a none null value (see commented out line in the controller) it will also work
I have replicated this behaviour in a small test project (this is deliberately very Noddy - just enough to replicate the problem)
Am I doing something fundamentally wrong or am I looking at coding some sort of work around here? (I realise that a Required nullable field sounds like a bit of a oxymoron, but I wanted to present the user with a blank field which they must then fill, not one pre-populated with an arbitrary date value)
Model
[Code]....
View (Auto generated)
[Code]....
[Code]....
I'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]....
I 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.
I 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)
I 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.
Right now I have an error if f.ParentID is null:
DataSet1.TreeItemRow[]
TreeItemRows = (from f
in tidt
where (f.ParentID == TreeItemId)
select f).ToArray();
I must continue if f.ParentID is null, I don't want to include null fileds in the array. What is the right syntax for that is linq sql?
When I run the code below, it works
int charId = int.Parse(Request.Params["charId"]);
EveFPT ctx = new EveFPT();
var theCharQuery = from a in ctx.tblChars
where a.id == charId
select new
{
Name = a.name,
CorpName = a.tblCorps.name,
AllianceName = a.tblCorps.tblAlliances.name
};
if(theCharQuery.Count() == 1)
{
var theChar = theCharQuery.First();
lblCharName.Text = theChar.Name;
lblCorpName.Text = theChar.CorpName;
lblAllianceName.Text = theChar.AllianceName;
}
However, If I the below
var theCharQuery = from a in ctx.tblChars
where a.id == charId
select a;
if(theCharQuery.Count() == 1)
{
tblChars theChar = theCharQuery.First();
lblCharName.Text = theChar.name;
lblCorpName.Text = theChar.tblCorps.name;
lblAllianceName.Text = theChar.tblCorps.tblAlliances.name;
}
the statement theChar.tblCorps always returns null.
Using linq to entities i am connecting to a database, the database has tables in it that has payments that have a multi to multi relationship with jobs. This is acheived via an allocs table. I want a list box with all the jobs that has a column called due price which takes all of the allocations of payments for this job and takes that away from the job price. However, using the below linq to entities statement. The problem is that if the job has no allocations it returns null and therefore the due payment is empty. What i really want is for the due payment to be the job price if there are no allocations however, i cannot think of a way around this.
var jobs = from j in data.jobs
where j.property.customer.id == customerid
&& j.completed != null
select new
{
j.id,
j.price,
dueprice = j.price - ( from a in data.allocs
where a.job.id == j.id
select a.amount ).Sum(),
lineone = j.property.lineone,
postcode = j.property.postcode,
jobtype = j.jobtype.name,
j.completed
};
I am using ternary operator in Eval,
code is
<%# (Convert.ToInt32(Eval("Url").ToString()).Length > 0) ? "No" : "Yes" %>'
its getting an error that tags are not formed properly.
I am using Listview to display the data. for a real estate website,
the problem is when the property is for sale I need to show price of sale Asking_Price or when it is for Rent i should display the Rent Amount Rent_amount field and when it's for sale and for rent i want to showboth records.
[Code]....
How to use ternary operator in this condition
if (drSiteDetail["sitetype"].ToString() == "Local")
rdbType.SelectedIndex = 0;
else
rdbType.SelectedIndex = 1;
am having problem with the Label statement. see the code below. The error (on Line ABC in the code below) I am getting is 'SampleCS.CRUDSample' does not contain a definition for 'lblMsg' and no extension method 'lblMsg' accepting a first argument of type 'SampleCS.CRUDSample' could be found (are you missing a using directive or an assembly reference?)
[code]....
[Code]....
I have a problem with my SqlDataSource, when the web form i loaded it works OK but when I execute an insert statement and then i execute the method DataBind(), the data in my grid view is not changed.
View 1 Replies I am new to all this, and ignorant beyond compare. I believe I have the same problem as this :
[URL]. However, the solution proposed for him doesn't seem to work for me. I have a session variable that 'march_cpi_session' that I wish to include in an sql select statement to multiply the values I get from a datatable before they're used to populate a gridview control. The session variable works fine elsewhere in my application, but causes a variety (depending upon how I fiddle about with the syntax) of sql errors. This is the currrent code:
[code]....
iam using webservice for create customer.by using WSDL(webservice) Url iam able to create customer Successsfully using Createcustomer request class. but in responce iam unable to get Unique ID the reponce object should generate as per SOAP functioanly iam unable to see the result set it is always null. How can i do this i need to capture that Unique ID after creating customer. it's Async mode. In below responce e.result set containning NULL values evn i customercreated in database.how to get my UniqueId in responce. my code:
{
Customer customer = new Customer();
PersonName pn = new PersonName();
pn.FirstName = txtFname.Text;
pn.LastName = txtLname.Text;
pn.MiddleName = txtMname.Text;
pn.Salutation = "Mr.";
customer.PersonName = pn;
CreateCustomerRequest ccr = new CreateCustomerRequest();
ccr.CreateCustomer = customer;
RSWS rsws = new RSWS();
rsws.CreateCustomerCompleted += new CreateCustomerCompletedEventHandler(rsws_CreateCustomerCompleted);
rsws.CreateCustomerAsync(ccr);
}
void rsws_CreateCustomerCompleted(object sender, CreateCustomerCompletedEventArgs e)
{
CreateCustomerResponse ccresp = e.Result;
Page.RegisterStartupScript("inspa", "<script>alert('customer created successfully')</script>");
}