This is actually a situation where LINQ as follow:
Code:
Dim query = From loadedfile In dtloadedfile.AsEnumerable() _
Join householdPanels In dtHouseholdPanels.AsEnumerable() _
On CType(loadedfile("Household_number"), Integer) Equals _
[code]...
when i get to col.DataType = t.PropertyType, i hit an error where it says Nullable datatype is not allowed. I know the t.propertytype returns nullable as datatype, however, this nullable type do have a normal datatype declared too. ie Of System.Nullable(Of Integer) from the LINQ query. But how do i get that information?
ps: this function is taken somewhere from the web, so you might recognise it.
I 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?
I have a simple Gridview control on .aspx page. All I am doing is selecting 3 or 4 fields from oracle database.When I have to_char() function it says "portfolio_rundate" is a not a valid field in the datasource. Wherease the same SQL perfectly works fine in oracle.
I want to filter by database result based on the current date. I have a grid layout which will display the result based on the current date. I am using parameterized query for getting the result but it is not working.given below is the query i am using
I want to extract list of parameters with data type and length.For example i give name of sp and i can able to find the list of parameters thet the sp expact with datatype and length of parameter.
i am store ms word resume to image(BLOB) data type in sql server 2005. now i want to display this resume in HTML page or in text area. and for that i use
I'm not sure the best way to explain this but I want to take results from a stored procedure and list them but not in a grid. I am listing user profiles and I want to display a picture, name, description and other info from each record. But I want each in a group. How is this done in asp.net?
I'm developing ASP.net project with C# using vs visual-studio-2008. when I drag drop asp control from tool box to the design view then I go to the code behind I should see the control in pop up object list. at the begin I had no problem but not when I drag and drop any new control I can not see it and even if I write it manually when give me an error this this name not exist.
I do not know how this has started but when creating new pages in a web project using vb.net coding, when I add any control such as a button or something else and then do to the vb code page for it, I click the dropdown on the left and it does not show the controls. What would cause this? I am using a master page with the page and the controls are going into the content sections. If I add a line like:
Code:
[code]....
then I have events. But in another peoject I do not have to do this. Is there a reason why? Maybe a setting that was changed? I'm using VS2008 in vb.net language.
I've taken over an ASP.NET project and the previous dev used "dynamic" DSNs sprinkled throughout the application. These data sources are databound to several controls throughout the site.I'd prefer to use a system DSN that I would define on my dev machine and the production web server. This way if I need to change the location of the SQL database I can just change the system DSN on the server instead of modifying the code and recompiling the application in Visual Studio.What is the easiest way to list all these dynamic DSNs that are in use in this web site project in Visual Studio 2008 and modify them to use a system DSN instead?
I have an SQL Function with the following SQL within:
SELECT StockID FROM (SELECT DISTINCT StockID, ROW_NUMBER() OVER(ORDER BY DateAdded DESC) AS RowNum FROM Stock WHERE CategoryCode LIKE @CategoryID) AS Info WHERE RowNum BETWEEN @startRowIndex AND (@startRowIndex + @maximumRows) - 1
I have a Parameter @CategoryID - however I need to take in a category ID such as "BA" and translated this to a list of Category IDs such as "IE","EG" etc so my WHERE clause looks like:
WHERE (CategoryCode LIKE 'IE' OR CategoryCode LIKE 'EG') AS Info
I have a Lookup Table which contains the "BA" code and then all the real category codes this means such as "IE" and "EG".How do I have the CategoryID expand to multiple "OR" statements in my SQL Function?
At the moment the query as shown can cope with one CategoryID such as "IE", this is done as I want a category page such as category.aspx where a parameter "BA" is passed such as category.aspx?category=BA and this page will list all items with the category codes "EG" and "IE".
The reason I need this is there is a "parent" category code which has multiple "children" category codes which are different to the parent code. I am using ASP.NET and .NET 3.5 on the front-end if this helps.
I 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).
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?
I 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.
I 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:
I have a small Linq to Sql database application, with a table set up with a datetime field (allow Null). I am able to submit 'Nothing' into the datetime field after setting my .dbml table | field | property to AutoGenerated = True. Why this is I don't know, but it works. Now that I can submit an empty datetime field to the database, I am having trouble loading it into an object with a property set as datetime.
Example: of property in object
Private _deliveryDate As DateTime = Nothing
Public Property DeliveryDate() As DateTime [code]...
Example: setting value when instanciating the obect
dim test as new dateObject(Nothing, ...) ' where (Nothing) represents the datetime field retrieved from the database set to null.When I try the above line I get "Nullable object must have a value."
I get this error "Type 'String' must be a value type or a type argument constrained to 'Structure' in order to be used with 'Nullable' or nullable modifier '?'." [:(]
Function Index(ByVal product As Product, ByVal category_1 As Nullable(Of String), ByVal category_2 As Nullable(Of String)) As ActionResult ... End Function
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.....)
