ADO.NET :: JSON Deserialize Into Entity Framework Object And Setting The DataMemberAttribute "Name="
Aug 24, 2010
I'm in the process of deserializing a JSON object into an Entity Framework object. The property names in the JSON do not match up totally with the property names in the Entity Framework Objects. What I'd like to do is set "Name=" on the "DataContractAttribute" for the table and the "DataMemberAttribute" for the properties in the Designer.cs file. I tried setting these in the Designer.cs file manually just to see if it would work - which it did (using JSON.Net) but of course when I went into the .edmx designer I lost all my changes. Is there a way to do this?
From VB.net code behind when I am trying to deserialize it it's stating that
"Expecting state 'Element'.. Encountered 'Text' with name '', namespace ''."
Deserialization code snippet:
Dim serializer = New DataContractJsonSerializer(GetType(List(Of Employee))) Dim memoryStream = New MemoryStream() Dim s = msg.Content.ReadAsString() serializer.WriteObject(memoryStream, s) memoryStream.Position = 0.......
public class AccessToken { public string access_token {get;set;} public DateTime expires { get; set; } } public class TokenReturn { public List<AccessToken> tokens { get; set; } } JavaScriptSerializer ser = new JavaScriptSerializer(); TokenReturn result = ser.Deserialize<TokenReturn>(responseFromServer);
I'm trying to figure out how to bind an EF4.0 object to my textbox control. I have a call to my business object that returns an entity CFUser that has a FirstName parameter on it of type string. However, after I make the call and bind the object, the codebehind executes which fills the BindUser property with the correct value. However, nothing shows up in the textbox.
I am using Json.Net however when I go to deserialize the following json I get that Json cannot deserialize to type List.
Json:
{"postalCodes":[{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10001","countryCode":"US","lng":-73.996705,"placeName":"New York City","lat":40.74838,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10019","countryCode":"US","lng":-73.985834,"placeName":"New York City","lat":40.765069,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10021","countryCode":"US","lng":-73.958805,"placeName":"New York City","lat":40.768476,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10022","countryCode":"US","lng":-73.965703,"placeName":"New York City","lat":40.757091,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10036","countryCode":"US","lng":-73.991826,"placeName":"New York City","lat":40.759724,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10065","countryCode":"US","lng":-73.96379,"placeName":"New York City","lat":40.76507,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10003","countryCode":"US","lng":-73.989223,"placeName":"New York City","lat":40.731253,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10010","countryCode":"US","lng":-73.981328,"placeName":"New York City","lat":40.737476,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10011","countryCode":"US","lng":-73.99963,"placeName":"New York City","lat":40.740225,"adminName1":"New York"},{"adminName2":"New York","adminCode2":"061","adminCode1":"NY","postalCode":"10012","countryCode":"US","lng":-73.998284,"placeName":"New York City","lat":40.72553,"adminName1":"New York"}]}
Is 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.
We have an ASP.NET MVC site that uses Entity Framework abstractions with Repository and UnitOfWork patterns. What I'm wondering is how others have implemented navigation of complex object graphs with these patterns. Let me give an example from one of our controllers:
[code]....
It's a registration process and pretty much everything hangs off the POCO class Person. In this case we're caching the person through the registration process. I've now started implementing the latter part of the registration process which requires access to data deeper in the object graph. Specifically DPA data which hangs off Legal inside Country.
The code above is just mapping out the model information into a simpler format for the ViewModel. My question is do you consider this fairly deep navigation of the graph good practice or would you abstract out the retrieval of the objects further down the graph into repositories?
I have a custom Javascript object that has a few string and float members. I'd like to serialize an array of them in Javascript, assign the result to a hidden field, and then retrieve and deserialize them in the codebehind for my asp.net application.
I am new to entity framework , it is really very good , but I want to know what is the difference between using entity framework with stored procedure or without stored procedure , which one the faster and what is the benefits for using stored procedures with entity framework.
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 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 use the JavaScriptSerializer class of ASP.net to serialize my object and return it to the client side. How can I deserialize the string using JavaScript?
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
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?
I 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:
Here'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.
