CODEWITHSUNDEEP
c#jsonentity-framework
Sahil Sharma
Sahil Sharma

Reputation: 37

Send relational data using Json to wcf services

Roles and Privileges have relationship 1 to many. but while retrieving roles i am getting null value "[]" for the privileges. I am using Json to send data to wcf services using EF6 having code first approach.

code :

System.Web.Script.Serialization.JavaScriptSerializer objJSSerializer = 
     new System.Web.Script.Serialization.JavaScriptSerializer();
string strJSON1 = objJSSerializer.Serialize((
        from role in  context.Roles select role)
       .ToList());

output:

[{"privileges":[],"users":[],"ID":1,"RoleName":"Admin","IsActive":1},

{"privileges":[],"users":[],"ID":2,"RoleName":"Apprisal Minister","IsActive":0}]

I tried context.Configuration.ProxyCreationEnabled = false; but still not able to get the privileges.

Basically, The problem, I am getting is that when i try to serialize the roles object. It doesn't serialize the relational data. I mean privileges are not there.

Which is the right way to get relational data in entity framework6.

Upvotes: 0

Views: 103

Answers (2)

Aydin
Aydin

Reputation: 15294

Entity framework has lazy loading enabled by default which means that related items are not automatically retrieved from the database.

Let's imagine you have a blog containing multiple blog posts, each blog post has an author and many comments

1 Post has 1 Author
1 Post has many Comments 
1 Comment has 1 Author
1 Author has many posts
1 Author has many comments

Now to retrieve a blog posts with the related author of the post, the comments and the authors of the comments, you need to use the Include() extension method on your DbSet<TEntity> with the name of the related type added as a parameter..

using(var context = new BlogContext)
{
     var blogsDetailed = context.Blogs.Include("Author")
                           .Include("Comments.Author);
 }

There may be syntax errors as I'm typing from iPhone but that's the idea behind it

Upvotes: 0

Thorarins
Thorarins

Reputation: 1904

Not sure if you mean load the Roles and it's related Privileges but this should work

var roles = dbContext().Roles.Include(r => r.Privileges);

And to serialize it use Newtonsoft.Json ( nugget package ) it handels relations but not circular refs. so if any references in Privileges to Roles , use attribute [JsonIgnore] on the properties 

 string json = JsonConvert.SerializeObject(roles);

Upvotes: 1

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