CODEWITHSUNDEEP
c#asp.net-mvcentity-frameworkasp.net-mvc-4
F Msw
F Msw

Reputation: 131

How to create two unique / primary keys with Entity Framework

I have these tables :

public partial class user
{           
    public string Id { get; set; }
    public string name{ get; set; }
}

and

public partial class book
{          
    public string book-id{ get; set; }
    public string book_name{ get; set; }
}

and I'm looking to create a table to hold the user(id) and book (book_id) only to ignore the duplication .

For example: suppose the new table name is Test :

id ->1
book_id->1
id ->2
book_id->2

if I send again this values :

id ->1
book_id->1

it should not add them to database, so how to define that? What should the new class (Test) property / constraint be? And thanks

Upvotes: 1

Views: 591

Answers (1)

CodeNotFound
CodeNotFound

Reputation: 23190

Just create a new class Test like this :

public class Test 
{
    [Key(Order=0)]
    public int UserId { get; set; }

    [Key(Order=1)]
    public int BookId { get; set; }

    public User User { get; set; }

    public Book Book { get; set; }
}

By doing that, EF will create a table named Test in your database. That table will not allow duplication because we use composite key (UserId, BookId).

After that you need to add navigational propertiy public ICollection<Test> Tests { get; set; } in Book and User.

Upvotes: 1

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