Questions tagged [model]
Part of the MVC pattern, the Model manages the behaviour and data of the application.
21,475
questions
43
votes
6
answers
8k
views
Ruby on Rails: Is it better to validate in the model or the database?
Is it generally better practice (and why) to validate attributes in the model or in the database definition?
For (a trivial) example:
In the user model:
validates_presence_of :name
versus in the ...
- 18.2k
43
votes
1
answer
40k
views
AttributeError: 'ManyRelatedManager' object has no attribute 'add'? I do like in django website but got this error
for item in data:
category_id = item['category_id']
del item['category_id']
category = Category.objects.get(pk=category_id)
code = item['code']
try:
article = Article....
- 15.7k
42
votes
4
answers
169k
views
How to set a hidden value in Razor
I know that what I'm trying to do is bad idea, but I have specific constrains for now.
I have multiple sites, using one and the same MVC3 code base. For one of them the requirement is to hide some ...
- 22.1k
42
votes
3
answers
77k
views
Call a model method in a Controller
I'm have some difficulties here, I am unable to successfully call a method which belongs to a ProjectPage model in the ProjectPage controller.
I have in my ProjectPage controller:
def index
@...
- 2,714
42
votes
4
answers
20k
views
Share types between client and server
I'm working on a project with a Node.js, Express.js & TypeScript backend (REST API) and a React, Redux & TypeScript frontend.
In the backend I have created some types for example:
models/...
- 811
42
votes
5
answers
19k
views
guidelines for where to put classes in Rails apps that don't fit anywhere
I'm wondering if there are any best practices about where to put non-standard Ruby files in Rails apps, those that don't fit in any of the default directories (controllers/models etc.).
I'm talking ...
- 7,677
41
votes
7
answers
48k
views
Rails Model without a table
I want to create a select list for lets say colors, but dont want to create a table for the colors. I have seen it anywhere, but can't find it on google.
My question is: How can I put the colors in ...
- 821
40
votes
3
answers
27k
views
How to get the app a Django model is from?
I have a model with a generic relation:
TrackedItem --- genericrelation ---> any model
I would like to be able to generically get, from the initial model, the tracked item.
I should be able to ...
- 588k
40
votes
4
answers
30k
views
How to implement Active Record inheritance in Ruby on Rails?
How to implement inheritance with active records?
For example, I want a class Animal, class Dog, and class Cat.
How would the model and the database table mapping be?
- 461
40
votes
2
answers
29k
views
Could not find the association problem in Rails
I am fairly new to Ruby on Rails, and I clearly have an active record association problem, but I can't solve it on my own.
Given the three model classes with their associations:
# application_form....
- 25.1k
40
votes
6
answers
12k
views
rails model has_many of itself
I have a event model. Events can have parent events, set from a column in the model (parent_event_id). I need to be able to do has_many :event on the model, so I can just do, for example, event....
- 2,854
40
votes
3
answers
25k
views
Rails Internationalization (I18n) in model validations: Possible or not?
I have the following validation in a model:
validates_inclusion_of :whatever, :in => [true, false], :message => I18n.t('please_select_whatever')
It seems that the translation does not work in ...
- 3,908
39
votes
5
answers
30k
views
Check if a OneToOne relation exists in Django
Now I'm using django 1.6
I have two models relates with a OneToOneField.
class A(models.Model):
pass
class B(models.Model):
ref_a = models.OneToOneField(related_name='ref_b', null=True)
...
- 18k
39
votes
3
answers
13k
views
Usage of MVVM in iOS
I'm an iOS developer and I'm guilty of having Massive View Controllers in my projects so I've been searching for a better way to structure my projects and came across the MVVM (Model-View-ViewModel) ...
- 31k
39
votes
6
answers
9k
views
Rails Models: how would you create a pre-defined set of attributes?
I'm trying to figure out the best way to design a rails model. For purposes of the example, let's say I'm building a database of characters, which may have several different fixed attributes. For ...
- 42.8k
38
votes
4
answers
48k
views
Tensorflow: How to convert .meta, .data and .index model files into one graph.pb file
In tensorflow the training from the scratch produced following 6 files:
events.out.tfevents.1503494436.06L7-BRM738
model.ckpt-22480.meta
checkpoint
model.ckpt-22480.data-00000-of-00001
...
- 479
37
votes
4
answers
17k
views
What is the Rails3 version of errors.add_to_base?
I want to write a custom validation in Rails 3, but following this example I get:
'ActiveModel::DeprecatedErrorMethods.add_to_base' call is deprecated in Rails 3.0
What is the rails3 version of:
...
- 18.1k
37
votes
6
answers
97k
views
Get Laravel Models with All Attributes
Is there a way to retrieve a model in Laravel with all the attributes, even if they're null? It seems to only return a model with the attributes that aren't null.
The reason for this is that I have a ...
- 2,295
37
votes
1
answer
16k
views
model.matrix generates fewer rows than original data.frame
Why doesn't a model matrix necessarily have the same number of rows as the data frame?
mergem = model.matrix(as.formula(paste(response, '~ .')), data=mergef)
dim(mergef)
# [1] 115562 71
dim(...
- 16.2k
36
votes
7
answers
49k
views
In Laravel, how do I retrieve a random user_id from the Users table for Model Factory seeding data generation?
Currently, in my ModelFactory.php, I have:
$factory->define(App\Reply::class, function (Faker\Generator $faker) {
return [
'thread_id' => 1,
'user_id' => 1,
'body' => $faker-...
- 10.7k
36
votes
7
answers
61k
views
This expression is not callable. Type 'Number' has no call signatures
Hi I'm new in Typescript, I have an object-type variable in which might be different values from different types or nested object. now my question is that how can I define a model for this object to ...
- 671
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votes
5
answers
114k
views
Update Table Using Laravel Model
I've got a table for a sports team. The record shows the team selection and some other information. I want to update the record with the team selection. My model is thus:
class Selection extends ...
- 567
36
votes
9
answers
25k
views
Django self-recursive foreignkey filter query for all childs
I have this model with a self referencing Foreign Key relation:
class Person(TimeStampedModel):
name = models.CharField(max_length=32)
parent = models.ForeignKey('self', null=True, blank=True,...
- 11.8k
36
votes
4
answers
20k
views
Required Attribute on Generic List Property
Is it possible to put a [Required] attribute onto a List<> property?
I bind to a generic list on POST and was wondering if I could make ModelState.IsValid() fail if the property has 0 items in it?
- 1,698
36
votes
2
answers
17k
views
How to have two models reference each other Django
I have the following code:
class Game(models.Model):
title = models.CharField(max_length=50)
summery = models.CharField(max_length=500)
key = models.IntegerField()
pin = models....
- 11.3k
36
votes
4
answers
28k
views
Rails: Serializing objects in a database?
I'm looking for some general guidance on serializing objects in a database.
What are serialized objects?
What are some best-practice scenarios for serializing objects in a DB?
What attributes do you ...
- 17.2k
36
votes
1
answer
6k
views
Best approach to model validation in PHP? [closed]
I've learned that there are often many ways to solve one programming problem, each approach typically having its own benefits and negative side affects.
What I'm trying to determine today is the best ...
- 18.7k
35
votes
4
answers
19k
views
Rails: belongs_to vs has_one
A bit of a newbie question on rails associations.
I have a Bug model, and a Status model. Status is basically just a key/value pair table. Out of the choices available, I would say Bug has_one Status ...
- 41.7k
34
votes
5
answers
50k
views
How can my django model DateField add 30 days to the provided value?
as the title suggests. I want to add 30 days to the DateField field. This is auto populated on creation of record using auto_now_add=True
Any ideas how to go about doing this?
Thanks
- 41k
34
votes
11
answers
43k
views
Models in the Zend Framework
What are some of the ways you have implemented models in the Zend Framework?
I have seen the basic class User extends Zend_Db_Table_Abstract and then putting calls to that in your controllers:
$foo ...
- 20.8k
34
votes
3
answers
28k
views
rails validate in model that value is inside array
I have a form where i pass a field named :type and i want to check if it's value is inside an array of allowed types so that no one is allowed to post not-allowed types.
the array looks like
@...
- 5,778
34
votes
10
answers
22k
views
How do I validate that two values do not equal each other in a Rails model?
I have a User model, which has an email and a password field. For security, these may not be equal to each other. How can I define this in my model?
user142019
34
votes
7
answers
36k
views
Django model instances primary keys do not reset to 1 after all instances are deleted
I have been working on an offline version of my Django web app and have frequently deleted model instances for a certain ModelX.
I have done this from the admin page and have experienced no issues. ...
- 905
34
votes
5
answers
41k
views
MVC :: What is a model?
I am at a point where I must make a decision about models. I am aware that models are what you use to do all your database manipulation. But are models restricted to this?
Are they meant only for ...
- 91k
34
votes
4
answers
32k
views
Kohana 3: Example of model with validation
I find examples and tutorials about models and about validation. And I places that say the validation (or most of it at least) should be in the model, which I agree with. But I can't any examples or ...
- 155k
33
votes
15
answers
90k
views
33
votes
6
answers
49k
views
Laravel 5 Models Folder
I have a directory called models inside app/ where I place all my model classes. Now I want to change the directory where the following command outputs the generated classes
php artisan make:model ...
- 2,609
33
votes
6
answers
14k
views
Rails: how to require at least one field not to be blank
I know I can require a field by adding validates_presence_of :field to the model. However, how do I require at least one field to be mandatory, while not requiring any particular field?
thanks in ...
- 12.6k
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votes
4
answers
44k
views
How to set initial data for Django admin model add instance form?
How can I set an initial value of a field in the automatically generated form for adding a Django model instance, before the form is displayed? I am using Django 1.3.1.
My model is the following:
...
- 3,918
32
votes
5
answers
17k
views
What is DOM? (summary and importance)
What is the Document Object Model (DOM)?
I am asking this question because I primarily worked in .NET and I only have limited experience, but I often hear more experienced developers talk about/...
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votes
2
answers
42k
views
Real example of TryUpdateModel, ASP .NET MVC 3
I can't understand, how to use TryUpdateModel and save the MVC architecture at the same time.
If I am not mistaken, work with datacontexts must be in the Model. So, such code
var db=new ...
- 2,338
31
votes
5
answers
111k
views
Laravel how to add a custom function in an Eloquent model?
I have a Product model
class Product extends Model
{
...
public function prices()
{
return $this->hasMany('App\Price');
}
...
}
I want to add a function which will ...
- 2,630
31
votes
2
answers
14k
views
Rails put validation in a module mixin?
Some validations are repetitive in my models:
validates :name, :length => { :minimum => 2 }, :presence => true, :uniqueness => true
validates :name_seo, :length => { :minimum => 2 },...
- 4,401
31
votes
4
answers
14k
views
difference between scaffold and model in Rails
What's the difference between generating a scaffold and generating a model in Rails? What are the advantages/disadvantages of doing either?
- 751
31
votes
6
answers
21k
views
Rails: change column type, but keep data
I have a model with a column of type integer which I want to convert to type string. Now I'm looking for the best way to change the column type without losing the data. Is there a painless way to ...
- 545
31
votes
3
answers
36k
views
Better option to check if a particular instance exists django
Which of the two is a better and efficient option to check if an instance exists. There can only be one record returned at most.
1) Use the filter option and see if it exists:
x = MyObject.objects....
- 11k
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votes
2
answers
20k
views
Access fields in Django intermediate model
I'm creating a Person Group and Membership as described in Django docs for intermediate model.
class Person(models.Model):
name = models.CharField(max_length=128)
def __unicode__(self):
...
- 2,789
31
votes
6
answers
22k
views
Laravel models: Where are model properties?
(I come from Visual Studio + Entity Framework background and trying to locate equivalent functionality in Laravel + Eloquent)
In EF and Visual Studio, we add a new Model to our application and just ...
- 34.4k
30
votes
4
answers
31k
views
Override django's model delete method for bulk deletion
I'm overriding Django's model delete method in order to delete orphan files in the disk for image fields, something like this:
class Image(models.Model):
img = models.ImageField(upload_to=...
- 1,329
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votes
4
answers
25k
views
How to set default value of TextBox empty string instead of null
I may be out of date, but one principle I adhere to is avoid nulls as much as possible.
However what I have found is that for a strongly typed view in which the user inputs the properties of an ...
- 10k