Easiest way to implement PUT API method to update entity

问题

I have a Web Api project and currently updating an entity is done via POST. Creating an entity is also done via the same POST method, and I implement by checking if the user has sent me an entity Id and then implementing an update as opposed to a create.

This is bad good for a number of obvious reasons. It's also confusing from a client perspective and makes the whole method slow and hard to define.

So I'm splitting updating into a PUT method, and I want it to be like so (psuedo code)

public string PUT(MyModel model){

    //Check if model Id is sent. return if not.


    //Check what other fields have been sent.


    //Update only those fields using EF and save.

    }

I would implement like:

var toUpdate = context.MyModels.FirstOrDefault(x => x.Id == model.Id);

if(toUpdate == default(MyModel)){ //Return error to client }

if(model.first != null){ toUpdate.first = model.first; }
//Repeat for every field.

context.MyModels.AddOrUpdate();
context.SaveChanges();

As I'm new to building API's I wondered if this is standard for creating PUT update methods. This might get closed as Opinion-based but I'd like to know if this implementation is okay as I've had no guidance in building this API really.

回答1:

For your case, I think you can implement like this.

try
{
    context.Entry<MyModel>(model).State = EntityState.Modified;
    context.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
    var msg = dbEx.EntityValidationErrors.Aggregate(string.Empty, (current1, validationErrors) => validationErrors.ValidationErrors.Aggregate(current1, (current, validationError) => current + (Environment.NewLine + $"Property: {validationError.PropertyName} Error: {validationError.ErrorMessage}")));
    var fail = new Exception(msg, dbEx);
    throw fail;
}

Actually, I prefer putting update code inside generic class, so that I don't need to write the update code for every entity

public void DoUpdate<TEntity>(TEntity entity) where TEntity : class
{
    try
    {
        Context.Entry(entity).State = EntityState.Modified;
        Context.SaveChanges();
    }
    catch (DbEntityValidationException dbEx)
    {
        var msg = dbEx.EntityValidationErrors.Aggregate(string.Empty, (current1, validationErrors) => validationErrors.ValidationErrors.Aggregate(current1, (current, validationError) => current + (Environment.NewLine + $"Property: {validationError.PropertyName} Error: {validationError.ErrorMessage}")));
        var fail = new Exception(msg, dbEx);
        throw fail;
    }
}

来源：https://stackoverflow.com/questions/32826420/easiest-way-to-implement-put-api-method-to-update-entity

标签

entity-framework

asp.net-web-api