ADO.NET :: Add New Entity With Attributes And Connect
Dec 26, 2010is it possible to add a new entity with attributes and connect them and store details in the entity i am usign ms2010
View 1 Repliesis it possible to add a new entity with attributes and connect them and store details in the entity i am usign ms2010
View 1 RepliesI have an existing, mature schema to which we need to add some new Product attributes. For example, we have Products.Flavor, and now need to add new attributes such as Weight, Fragrance, etc. Rather than continue to widen the Products table, I am considering a couple of other options. First is a new Attributes table, which will effectively be a property bag for arbitary attributes, and a ProductsAttributes table to store the mappings (and values) for a particular product's attributes. This is the Entity-Attribute-Value (EAV) pattern, as I've come to understand it. The other option is to add a new column to the Products table called Attributes, which is of type XML. Here, we can arbitrarily add attributes to any product instance without adding new tables.
What are the pros/cons to each approach? I'm using SQL Server 2008 and ASP.NET 4.0.
And not doing a View that connect two tables ?Is there a way to connect two entities together in one new entity?
View 1 RepliesI am seriously at a loss here. The three things that will not change in this project are the fact that we are using the Entity Framework to do our data access, the fact that we want thorough unit testing and that our UI is asp.net. My question is how the hell do you make this work in Asp.net? E.g. You can use an ObjectDataSource to connect a method to a control, but if this control is a FormView you have all these problems [URL] to deal with and it simply doesn't work.
Furthermore, with grids, you don't get paging or sorting out of the box unless you use an EntityDataSource which basically circumvents your entire application. I can't be the only person who cries at this. What do you do?
A relative newcomer to .net MVC2 and the entity framework, I am working on a project which requires a single web application, (C# .net 4), to connect to multiple different databases depending on the route of access, (ie subdomain).
No problem with this in principle and all the logic is written to transform the subdomain into an entity connection and pass this through to the Entity Model.
The problem comes with the fact that the different database whilst being largely similar in structure contain 3 or 4 unique tables bespoke to that instance.
To my mind there are two ways to solve this issue, neither of which i am sure will be possible.
1/ Use a separate entity model for each database. -Attempts down this route have through up conflicts where table/sp names are the same across differnt db's, or implicit conversion errors when I try and put the different models in different namespaces. or
2/ Overwrite the classes which refer to the changeable database objects based on the value of a base controller property.
My question is if either of theser routes can ever work in principle or if i should just give up on the EF and connect to the dtabases directlky using ADO. Perhaps there is another way to solve this problem i haven't thought of?
In Visual Web Developer-2010, I have been trying to connect to IBM DB2 Database after installing the DB2 9.7 client (both supports VS2010/.Net4) so that I can use "ADO.NET Entity Data Model", but while clicking "New Connection" I can only see the list of Data Sources and Data Provider only related to MS SQL server. This is totally blocking my work, I am not able to work further since I cannot even establish the connection to my db2 database using this new editor so that I can create the edmx files in the solution for non MSSQL databases. Kindly provide me the solution ASAP, since my further work is blocking due to this.
View 2 RepliesI am using the following XML structure
<SERVERS>
<SERVER NAME="A1" ID="1"></SERVER>
<SERVER NAME="A2"></SERVER>
<SERVER NAME="A3" ID="3" Parent="XYZ"></SERVER>
<SERVER NAME="A4" ID="4"></SERVER>
<SERVER NAME="A5" Parent="abc" value="10"></SERVER>
<SERVER NAME="A6"></SERVER>
</SERVERS>
I am accessing this xml file by using LINQ to XML in asp.net by using C#. I am able to access all the attributes of an XML node by explicitly specifying the name of the attribute. I want to write query on this xml file which reads all the attribute values of the xml node (In our example the node is SERVER) dynamically means I want to write the query which can read the read the value of the attribute Name & ID from first node, only name from second row, Name, ID & Parent from the third row , Name & ID from the fourth row, Name, Parent & Value from the fifth row & only Name from the sixth row without modifying the existing code every time. Once I add one of the attribute ( for example if I add the attribute ID in the sixth row ) in the above xml file then I dont need to modify my LINQ to XML query. My query should dynamically fetch the total number of attributes & display their values. Is their any way to do this ?
I have an EDM, it includes the entities extension and history. My goal is to use history to keep track of all the changes made to extension entity. For example, if extension with ID 223 has its property 'Name_Display' changed - I want the history entity to record this.
I'm using ASP.NET with VB.NET. Where in my code do I put the hook to say, "update the history entity" and what should that hook look like?
i want to conncet to rss orignal website if connect is successfully write the rss to xml file and read from orignal website ,else connect failed read xml file (last information in rss original website) and show it how can do it .
View 1 Repliesgetting data from multiple Entities models into an MVC controller. Most of the examples I have seen for using EF in an MVC2 app only use a single entitiy.
I have just started using MVC2 in C# using the Entity Framework models (CIOps.model) created from an SQL database. I can create the controller and views using single tables of the model in MVC2, but I just cannot get my head around how to get data from multiple entity tables into the controller (similar to joins in T-SQL). I have included an example below of the controller code that works with a single entity table, tbl_tours (tbl_tour in DB).
Could someone please illustrate how this code would be changed to include additional columns from FK tables in addition to tbl_tours columns. E.g. the clients name from the tbl_clients, the coordinators name from the tbl_employees, and costs from tbl_costs entities? Is it possible to do this directly using the EF model entities/classes that are already created and not use LINQ, POCO, Repositories, etc.? The FK relationships are already in the EF models. I have included the whole controller code, but I just need a few examples of how to join the multiple entities, not rewrite every CRUD function function in the controller. I think this will get me over the hump in using EF in an MVC2 App. Also ignore the fact I am using the home controller, this will change in the application.
[Code]....
I get an cast exception when i am trying to insert an entity in Entity Framework (using code-first). From this code :
public virtual T Insert(T entity)
{
return Context.Set<T>().Add(entity);
}
The cast exception is like "impossible to cast ...Collection'1(Entity) to type (Entity)" I can't figure out why. I am pretty sure ive done everything right. Post entity
public class Post
{
public long PostId { get; private set; }
public DateTime date { get; set; }
[Required]
public string Subject { get; set; }
public User User { get; set; }
public Category Category { get; set; }
[Required]
public string Body { get; set; }
public virtual ICollection<Tag> Tags { get; private set; }
public Post()
{
Category = new Category();
if (Tags == null)
Tags = new Collection<Tag>();
}................................
I am mapping a stored procedure to an entity by right clicking on the entity (in the .edmx) and selecting "Stored Procedure Mapping." This brings you to a Mapping Details - "Name of Entity" Window that allows you to select the insert, update, and delete stored procedures associated with the Entity. It also maps the stored procedure parameter to the Entity "Property" (Column).
I'm gettin an error "error 2042: Parameter Mapping specified is not valid." The cause of the error is fairly obvious, in the Insert stored procedure that has been selected, a 'CHAR' parameter is being mapped to an Int32 Entity Property. I altered the stored procedure parameter to match the entity, I deleted the stored procedure, readded, and reslected it as the Insert function. I also cleaned, validated, updated model from database. No matter what I do, the parameter list in the mapping details doesn't reflect the change to the stored procedure. It's stuck on a char --> int32 mapping, even though it has been changed, like it's buried deep in meta data some where.
I am trying to add a new entity and have to refernce associated data to add it. I cannot load the Referencetables. Giving "The EntityReference could not be loaded because it is not attached to an ObjectContext." How do i complete this task in Entity Framework 3.5
[Code]....
I have a stupid problem with the Entity Framework. I get the following Exception:
[Code]....
I have an entity with a 4 fields representing the primary key. I copy it via serialization (works fine). I set the old entity to not valid (Datefield set to a date in the past, this field is part of the PK) and set the copied entity to DateTime.Now.Date. When I call context.AddObject I get the Exception above. I tried copying the entity via reflection but the entity has 3-4 references. And when copied, I get another Exception before even Adding the entity to the context. I also tried setting newObj.EntityKey = null and reset all the fields neccessary for the PK. I just want a whole copy of an entity with a different primary key (and some other fields changed too) and Create it in the database.
I'm writing a custom .NET MembershipProvider (not the built in one) and trying to update using Entity Framework. But of course i have no access to (Try)UpdateModel. How can i update it?
View 3 RepliesI have an Events table and an InstallmentPlans table. The relationship is 0..1 : an Event can have 0 or 1 Installment plans. If I want to remove the existing InstallmentPlan for an event, how do I do this? Setting it to null doesn't seem to work:
_event.InstallmentPlan = null;
Does ASP.NET provide any built in functionality for converting a named entity into its corresponding entity number? For example, I want to convert to , " to " and so on.
View 3 RepliesHere's a simple code snippet where I create a new Entity object and call SaveChanges() to create a new record in the mapped database table.
[Code]....
What I'm trying to figure out is whether there is a way to derive this new key for my entity, e, from the ObjectContext, m? The reason for this is that the way my actual code is structured, my entity object is already out of scope at the point where I call the SaveChanges() method.
I am trying to do something like this:
[Code]....
But ofcourse it is not working as I want to. The Ordering works on Question.Order, but I would also the
Questions.SubQuestions List to be ordered according to SubQuestions.Order
how to add and connect iis5.1 and how to add web config..
View 2 RepliesIs there a way to export a EF 4.0 Data Model to EF 3.5?
I looked around and found that we are not able to access EF 4.0 from a ASP.Net 3.5 project here: [URL]
Our project is the 1st to go to .Net 4.0 using Entity Framework and we (the team) were wondering if there was a way for the other projects that "might" need to access our data that are still using the .Net 3.5 framework.
I'm using .Net 3.5 with SP1.
I'm not sure about the difference between entity name and Entity Set Name
I have a create view that I cannot set HTML attributes on. I have tried various ways but still cant set an attribute. Currently I'm trying this
<%: Html.TextBoxFor(model => model.itinerary, new { size = 60})%>
I have a usercontrol that I load dynamically:
Code:
Sub PageLoadEvent()
Dim ctlIntrotext As Control = LoadControl("tryktabKapacitet.ascx")
plh1.Controls.Add(ctlIntrotext)
End Sub
and then adds the sub to the Page_load, that works fine.However:
1) How do I call subs from the usercontrol?
2) How do I add the OnClick-events which I normally have in the webform source, see example...
Code:
<uc9:TryktabKapacitet ID="TryktabKapacitet1" OnBtnNulstilClick="TryktabKapacitet1_BtnNulstilClick" OnSetAllModulesK="TryktabOptimering1_SetAllModules"
OnSetOneModuleK="TryktabOptimering1_SetOneModule"
OnBtnClick="TryktabOptimering1_BtnClick" runat="server"></uc9:TryktabKapacitet>
I have a web form with usual elements (first name, last name, etc). The Postback URL is a different website altogether as the form is intented to post lead information to another website.
The site that accepts the lead is expecting First Name to come over as "FName", and Last Name to come over as "LName". Is there any way I can set the ID of a textbox to "txtFName", but submit it over the wire as "FName"? I tried changing the name attribute, but at runtime it sets the name = id.