EF 将子实体添加到父实体

Question

I'm trying to add a child entity to a parent entity. The child being User whilst the parent is CheckoutToken :

Inserting the CheckoutToken:

 public async Task Insert(CheckoutToken model)
 {
    var checkoutToken = new Data.Models.CheckoutToken {
        Token = model.Token,
        License = _dbContext.Licenses.Single(l => l.Id == model.License.Id),
        Created = model.Created,
        Expires = model.Expires
    };

     checkoutToken.UserId = model.User.AspNetUserId;
     checkoutToken.User = await _userManager.FindByIdAsync(model.User.AspNetUserId);
     await _dbContext.CheckoutTokens.AddAsync(checkoutToken);
     await _dbContext.SaveChangesAsync();
 }

For some reason I get this exception:

Violation of PRIMARY KEY constraint 'PK_AspNetUsers'. Cannot insert duplicate key in object 'dbo.AspNetUsers'. The duplicate key value is (73a0c19b-a7b1-4462-8e82-12be55e47002). The statement has been terminated.

I don't understand why it's trying to create a user?

Answer 1

try commented this line:

public async Task Insert(CheckoutToken model)
 {
    var checkoutToken = new Data.Models.CheckoutToken {
        Token = model.Token,
        License = _dbContext.Licenses.Single(l => l.Id == model.License.Id),
        Created = model.Created,
        Expires = model.Expires
    };

     checkoutToken.UserId = model.User.AspNetUserId;
     // checkoutToken.User = await _userManager.FindByIdAsync(model.User.AspNetUserId);
     await _dbContext.CheckoutTokens.AddAsync(checkoutToken);
     await _dbContext.SaveChangesAsync();
 }

this because you try create new user with same data of an existing, if you need assign an existing user to an new entity only assign the Id of User not the full object