ASP.NET Core - using a form to partially update existing data-CodePudding

How do I update a model partially using a form? In other words, how do I update the data in a database for a model that may have 50 fields, but I only want to update two of them via a form? I have a model that has a form. That model has 30 fields, but I only want to update the date of birth and a description in the model's data through the form.

How do I do that without having to grab the data from the database beforehand?

For example:

Applicant has 30 fields, but I only need to update the Applicant's last name and date of birth, so my form ONLY has these fields in it for updating. How do I update JUST those two fields without wiping out or using default values for the others? Is that a view model?

Thank you!

CodePudding user response：

Try Attach method. You will need to set primary key for the entity and mark fields you need to update as modified

var entity = new SomeEntity()
{
    Id = id, // primary key
    SomeProperty = newvalue,
};

dbContext.SomeEntities.Attach(entity);
dbContext.Entry(entity).Property(x => x.SomeProperty).IsModified = true;
dbContext.SaveChanges();