BasicOdata.cs

[HttpPost]
public async Task<IActionResult> Post(Entity model)
{
    _db.Entities.Add(model);
    await _db.SaveChangesAsync();
    return Created(model);
}

[HttpPatch]
public async Task<IActionResult> Patch([FromODataUri] int key, Delta<Entity> model)
{
    var entity = await _db.Entities.FindAsync(key);
    model.Patch(entity);
    _db.SaveChanges();
    return Updated(entity);
}

[HttpPut]
public async Task<IActionResult> Put([FromODataUri] int key, Entity entity)
{
    _db.Entry(entity).State = EntityState.Modified;
    await _db.SaveChangesAsync();
    return Updated(entity);
}

[HttpDelete]
public async Task<IActionResult> Delete([FromODataUri] int key)
{
    var entity = await _db.Entities.FindAsync(key);
    _db.Entities.Remove(entity);
    await _db.SaveChangesAsync();
    return StatusCode((int)HttpStatusCode.NoContent);
}