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 SP db.sp_GetProfitMatrix , it takes nullable integer parameters, for which I have a default . It refuses me when I try to pass a null value (the two date parameters are nullable in the Linq designer) I get {"Nullable object must have a value."} error. here is my code:
int? nlDt = null; var pms = from p in db.sp_GetProfitMatrix( nlDt.Value, nlDt.Value) select new { p.Volume, p.GrossSales, p.NetSales, p.COGS };
I've got a detailsview control on a page. The table that it interacts with has a DateTime column in it. This column is nullable, and a lot of the records have null for that value. In the EditItemTemplate I've got a calendar control. When I try to put the DetailsView into edit mode, I get the following error message:
System.InvalidCastException was unhandled by user code Message=Specified cast is not valid. Source=App_Web_srpmlyjd StackTrace: at ASP.entries_aspx.__DataBinding__control44(Object sender, EventArgs e) in c:inetpubwwwrootMediaLibraryEntries.aspx:line 103 at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) at System.Web.UI.Control.DataBindChildren()
I am convinced that the problem is the null values in the DateTime column of the table. I've done some web searches on this, and some have suggested placing some dummy values into that column, but that seems more like a kludge, rather than a solution. How do I keep nulls in the table, and yet not have that preceeding error come up when a user tries to edit the selected record?
xamount is receiving this message on the last line. The session is being set in the previous page. Is there a way to resolve the message or should I just use a previous page postback
I am getting an exception on a linq to sql query:The null value cannot be assigned to a member with type System.DateTime which is a non-nullable value type.
I got the following error when i tried to insert a new record after the run my project, so what does this error indicates?
"{"Cannot insert explicit value for identity column in table 'Articles' when IDENTITY_INSERT is set to OFF."} System.Exception {System.Data.SqlClient.SqlException}
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:-
I have a listivew that is assigned a datasource in the code behind based on query string options. From what i have found out, once there is no datasource assigned in listview html then the sort feature stops working automatically and you must put the code in the _Sorting event. I cannot find a good example of this logic.
I am writing a plugin to help with a current ERP system we have that I am not allowed to modify the data structure at all. The table I am dealing with has over 100 columns and I am wanting to set my linq object propertychanged event and submitchanges or do I really have list out each property and set it equal to the new one?Below is an example of what I am trying to do:
Like that I have large number of controls on my form. I have dought, if I assigned like this, db.usp_ATI_FetchPatientDetails(iPatientID).ElementAt(0).Last_Name.ToString(); to every control, then I have set of controls like,
My question is that, for each control the Stored Procedure called or not? If it is yes then it is time consuming and I need to use LINQ to DataSet or LINQ to Object rather than to call SP for each control. What is difference between LINQ to DataSet and LINQ to Object?
I have some dropdown list boxes that I need to fill with data from a database but I also need the first option to be "Show All"... So I need to combine using a datasource and manually adding an item to the top of the list. I have tried two different ways with no luck:
1. with the appendDataboundItems = true, on aspx page, and below code in codebehind:
I am declaring a list in my class, populating the list in page load and using the list in various methods in this class. But, I get this error at every instance where I use this list in the methods. Error: System.NullReferenceException: Object reference not set to an instance of an object.
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 page that has a datasource. The datasource executes a stored procedure and returns results. If the result is NULL, I'd like to forward the user to an error page. How would I accomplish this with ASP.NET and C#?
public IEnumerable<Customer> GetCustomers() { Table<Customer> custObject = context.Customers; IEnumerable<Customer> filteredCustList = from customer in custObject select customer; filteredCustList; } GridView2.DataSource = utilLinqClass.GetCustomers(); GridView2.DataBind();
(no errors at build time or at compile time) Error I am getting is: An attempt to attach an auto-named database for file App_Dataaspnetdb.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
I need to retrive a value from a column of a table per stored proc. This is usually an integer, but also can be null. I get this value and store it in a session variable.
Later, I need to pass this same session variable to another stored proc.
Session["myVariable"] = ds.tables[0].rows[0][1]; // this can be null or an integer
somewhere else in the project, I need to pass it to another stored proc exactly as received.
here is my update query syntax.my problem is.if i update only logo1 and logo3 with null logo2 and img null then my query should be update the other record.just dont update null value record but other should be update.but below my query can not update any record.
UPDATE tbitem set itemname= @itemname,note=@note, price=@price,qty=@qty,logo1=@logo1, logo2=@logo2,logo3=@logo3,img=@img where id =@id and @logo1 is null and @logo2 is null and @logo3 is null and @img is null
I get a recordset returned from DB and try to load it. However sometimes field "LastRun" may be empty (NULL). when i have this it compiles fine but errors out when value is null m_LastRun = Convert.ToDateTime(r["LastRun"]); when I take out Convert.ToDateTime it doesn't even compile.
How can i get the values even when the Source or url is null from the below query
SELECT a.id, isnull((SELECT STUFF((SELECT '<li><a href="'+url+'">'+Source_Name+'</a> <span>(' + k.Source +')</span></li>' end FROM table1 i, table2 k, table3 j where i.CategoryID = j.Category_ID and i.CategoryID = c.Category_ID and i.Source = k.ID FOR XML PATH('')),1, 0, '')), '') AS Source_url, FROM @table4 c INNER JOIN table5 v on c.Category_ID = v.Category_ID
I have a datareader like so but when it encounters a NULL database value, I get the error message "Conversion from type 'DBNull' to type 'String' is not valid."
Dim myReader As SqlDataReader = myCommand.ExecuteReader() Dim yValues As New List(Of Double) With myReader If .HasRows Then While .Read yValues.Add(Double.Parse(.GetValue(0)))........