Imagine I have 3 classes (student has Marks which has subjects)
[Code]....
I got a List<Student> populated with all the student and nested collection of corresponding Marks and subjects.How do I, before binding this list to any grid, filter records to display only those students, who surely have appeared in subjects with name "X" and "Y"?I tried something like:
I have an ASP.Net app that retrieves a collection of roles for a given user. Each role is a string. There's rarely more than 2-3 roles for any one person.I wanted to store the colelction of roles in Session state to save the time accessing the DB on each request.I basically want to write code that checks if a given string exists in the collection to test if the user has that role or not.My question is...what's the best way to do this? Is an array the best collection to store the role strings in Session with? Or is a dictionary better? I figure an array will take less memory (I don't really need a key + value) although a dictionary might lookup faster.
I'm constructing a query using linq, but I'm having trouble using a collection, i.e. where field in database = anything in the collection.
Below is an example of what I mean:
dim keywords as string ="test,test2,test3,cats,dogs,frogs" Dim getKeywords = (From cp In myDataContext.pages Where cp.pageKeywords = currentPageKeywords.Split(",")
The aim of the above code is to return all records where the "pageKeywords" field contains 1st keyword, or 2nd keyword, or 3rd keyword etc.
I am writing an application in C# that uses LINQ to validate a datacontext off a textbox to see if the record exists already. If the record does exist I inserted an if statement to advise the user that the record exists, if the record does not exist I would like to allow the record to be added to the database. If I take out my else statement everything works fine as far as inserting goes, but I do not want to allow inserts in this scenario. I have tried moving the if and else statement to different parts of the code but can't quite figure this one out.
List<ReservationSlotLimitDetailEntity> sorted = (from p in slotLimitCollection.OfType<ReservationSlotLimitDetailEntity>() where p.DayOfTheWeek == dayOfTheWeek select p).ToList<ReservationSlotLimitDetailEntity>();
I want to sort in such a way so that it will add on more temp column "DayName" based on condition such that if dayOfTheWeek==1 DayName=Monday and if dayOfTheWeek==2 DayName=Tuesday and so on.
I'm new to LINQ and have a problem with my query not showing me the Table Collection. I manually created my Cart class and specified the table attributes on each property (works fine for inserting records via LINQ see below). DataContext dc = new DataContext(Conn);
var q = (from c in dc.NOTABLES?? where ((c.UserID == userID)) orderby c.CreateDateTime Based on examples I would expect to see dc.Cart But I don't, so I tried to access it via dc.GetTable<Cart>() which at least gets me data but doesn't seem to convert the rows to my Cart object since this: foreach (var cart in q) Log.Info("UserID: " + cart.UserID + " CartID: " + cart.ID.ToString()); blows up with a "Specified Cast is Not Valid" exception.
No Problem Inserting Also, I had no problem inserting data into the database:
DataContext dc = new DataContext(Conn); Table<Cart> Carts = dc.GetTable<Cart>(); Cart aCart = new Cart(); aCart.UserID = userId; aCart.Description = description; aCart.CreateDateTime = System.DateTime.Now; aCart.UpdateDateTime = System.DateTime.Now; Carts.InsertOnSubmit(aCart); Carts.Context.SubmitChanges();
I have a partial class extending my Entity Model. I'd like to write a method that returns a collection of types from my entity framework model. For example, I'd like to get all the states to populate a drop down list. So I've written a method called getallstates(), similar to the example below:
[Code]....
I tried returning a list of Objects, and a list of states to my calling method to be used to bind to a drop down list. However I get an error that:
Server Error in Application. Unable to cast object of type 'System.Data.Objects.ObjectQuery to type 'System.Collections.Generic.List`1[System.Object]'.
I'm new to linq. here is the scenario i need to write query for.I have a "Candidate" table with a varchar property "Skill"I have the table OR-mapped with LINQ to SQL on dbml file. Now I want to write linq query that:Selects all Candidates that have skill containing any of the keywords from ("asp.net","php","java")
I have a "simple" method that takes a Linq entity containing the information I want to update. The method then creates a list of counties the information is to be updated for, and tries to update the information for each county.
So user goes in fills form out selects update All counties, and the information in the form should be updated for all the counties for the member. Here is the code.
[Code]....
The first pass through the foreach runs perfectly, the second time through I get an error: Cannot attach an entity that already exists.
What is best way to work around this?
I have though about putting the foreach loop in my business_logic layer, and have it pass both the newRecord and OldRecord, but figured I would ask, before making the code change.
I would like to check whether a folder exists or not if not create. I'm sure this folder exists, but for some reason I get "false" when I check with "Exists" method.
The only reason I think could be because of the W: drive? I moved this application to production site and even there it returns false.
while I'm type in Windows explorer on my localhost and on the server "W:/Webs/ASPPages/cropper/uploads" it opens this folder. So my localhost and IIS server has W: mapping.
for test I tried to create the folder then it says can't find the path...
userFolderName = @"W:/Webs/ASPPages/cropper/uploads" //I also tried @"W:WebsASPPagescropperuploads" //I also tried @"W:WebsASPPagescropperuploads" //I also tried "W:\Webs\ASPPages\cropper\uploads" DirectoryInfo dirInfo = new DirectoryInfo(userFolderName);........
I have a list of objects that I want to bind to a gridview. Creating that list and binding it works fine for most of the public properties in that list.
There are some objects contained in each of those objects... for instance there is an Address object.
object.Address.Line1;
object.Address.Line2;
When I bind this to my gridview, I have no issues with stuff like object.DateRegistered, but how can I access things like object.Address.WhatEverProperty? I always get this error:
"A field or property with the name 'xxx.xxxx' was not found on the selected data source."
I have an ASP.NET app with lots of textboxes all over the page that need updating at various points through program execution.
These textboxes actually belong to a certain class, so for easy updating I thought I could create a Dictionary(Of string, object) and add the control.ID and the control to it and then for updating do something like this:
(in case of updating textbox.text):
[code]....
However the text property of the textbox does not actually get updated. I'm mainly trying to avoid having to manually do textbox.text = somestring for each one of my textboxes every time I have to update them.
I know that if I have set a cookie on a previous request, it will show up in my Request.Cookies collection. I want to update my existing Cookie. Are the cookies from my Request.Cookies collection already copied to my Response.Cookies collection? Do I need to add a new cookie with the same key using Response.Cookies.Add(), or do I need to use Response.Cookies.Set()?
I'm using HttpModule to capture requests to the web server. Before processing the page I'd like to check the values contained in some keys of the Request.Form collection and according to some logic change if necessary. I'd like to do this when BeginRequest event is fired. The problem is that the Request.Form collection is readonly.
List<Dictionary <string,object>> I am reading about the list and collection, If possible, what are the different ways that I can utilize the list of dictionary collections..... gives me different examples or areas where I can use it.
I am struggling to create a webservice method using LINQ technology and to populate a dropdown in a form. Here is the Webservice code.
[WebMethod]
public string[] GetAllCountries() { LinqClassesDataContext db = new LinqClassesDataContext(); var q = from c in db.ListContinents()select c; return q.ToList() ; }
And here is the form code behind
protectedvoid Page_Load(object sender, EventArgs e) { WSClass WS = new WSClass();//bool ds = WS.GetAllCountries(); var v = WS.GetAllCountries(); ddlContinent.DataSource = v; ddlContinent.DataBind(); }
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've build a linq query.But i want a random selection so its not always ID : 1,2,3,4,5,6 How can i randomize this var? I like to bind it to a repeater.//TagCloud:
Random rand = new Random(); var tc1 = from i in JumpTide.cms.menu.GetMenuItems(32) select new
string strCondition = "FirstName=='abc'" from p in People.Where(strCondition) select p
In our architecture we are usign both Linq-Sql as well Linq-Entity. So please give some thoughts wehter it is possible or not and is there any way to perform this?