i'm new to php and codeigniter but i have experience with pylons and sqlalchemy.
there you define model classes and then you use command something like "paster setup-app development.ini" and (paster?) creates tables for you and you dont have to write any sql code...
i was trying this with codeigniter and datamapper but so far i'm not sure if it is possible. so here i am asking you if it is possible?
i am very confused because in "models/" you can put your own classes (like in sqlalchemy). in these classes you define every attribute, relationship and other stuff. so why would you need to write the same thing 2 times? (1st in this class 2nd in sql script)
That is not possible, Datamapper implements the Active Record pattern which expects the tables to be there.
There is no need to define any attributes in a Datamapper model, it will be fetched from the associated table (and cached).
Related
I'm building an application in CakePHP 3. It uses a number of legacy databases which are not built in the Cake conventions.
I do not want to use any of the ORM features Cake provides, as it's more tedious to set up all the relations than just write "Raw SQL". We are also not going to make any changes to the database structures, so the ORM is a non-starter. So I'm going to write raw SQL queries for everything.
However, I'm not sure where this code would be put. I've read https://book.cakephp.org/3.0/en/orm/database-basics.html#running-select-statements but it doesn't say where you actually put that code.
I don't want to put my queries in a controller ideally since that defeats the purpose of MVC.
All I really need is one Model where I can put all my queries in different functions and reference them in my Controller(s).
In Cake 2.x it was easy to just create a model under app/Model/ then load it (loadModel) where needed in controller(s). But with the new Cake 3.x Table and Entity spaces, I'm not sure how this fits in?
I've also read up on Modelless Forms but don't think they're right either. For example the initial page of the application shows a list of chemicals which is just a SELECT statement - it doesn't involve forms or user input at all at this stage.
Obviously there will also be situations where I need to pass data from a Controller to the Model, e.g. queries based on user input.
As mentioned in the comments, I would suggest to not ditch the ORM, it has so many benefits, you'll most probably regret it in the long run.
Setting up the tables shouldn't be a big deal, you could bake everything, and do the refactoring with for example an IDE that does the dirty work of renaming references and filenames, and then set up the rules and associations manually, which might be a little tedious, but overally pretty simple, as there shouldn't really be much more to configure with respect to the database schema, than the foreign keys, and possibly the association property names (which might require updating possible entities #property annotations too) - maybe here and there also conditions and stuff, but oh well.
That being said, for the sake of completeness, you can always create any logic you want, anywhere you want. CakePHP is just PHP, so you could simply create a class somewhere in say the Model namespace (which is a natural fit for model related logic), and use it like any other class wherever needed.
// src/Model/SomeModelRelatedClass.php
namespace App\Model;
class SomeModelRelatedClass
{
public function queryTheDatabase()
{
// ...
}
}
$inst = new \App\Model\SomeModelRelatedClass();
$results = $inst->queryTheDatabase();
See also
Cookbook > Database Access & ORM > Associations - Linking Tables Together > BelongsTo Associations
I have read a book about MVC last week and a general one about design patterns, but I'm still confused as to where SQL queries belong in my code: the model or in the controller?
Let's take a very simple example, where you have a /popular page that will print the 5 most popular stories on a website.
In your model, you would have a class for prepared staments, and a class for assisting in the creation of the SELECT query. In your view, you'd have the HTML elements that display the /popular page.
Where does the query "SELECT most popular stories LIMIT 5" belong to? Is that something a controller class should ask, taking query methods from the model and passing to the view, or should the query be declared instead on a model class related to the /popular page?
Is the distinction even relevant? Would placing that query on the controller or the model be both considered professional ways to build a MVC?
Thank you. It seems most people get stuck understanding what to place on controllers
Edit: thanks for help everyone. Unfortunately as a new account I can't upvote any helpful posts yet
Usually (based on my experiences with MVC frameworks) the model layer takes care of database-related stuff in MVC.
Consider following approach:
Create abstract class which covers all the DB operations (selects, updates, etc). Each table would be a PHP class extending such class. You can then define DB table name in for instance private field, constructor or depending on model name.
Each controller (or the single controller) would load desired model, and use its methods to fetch data as associative arrays or objects, delete the data, change it.
After all DB operations have been done, controller returns view and passes data as its parameters.
Note that models are great place to put all the validation rules, and some helper methods due to the fact that they can be easily tested in PHPUnit.
I am new to Symfony2 and I am not sure where I should save a class that updated multiple tables(entities).
From reading documentation and tutorials it says I should not put any other tables reference within the entity class; I could put it within the controller class, but again many people have said this class should be as simple as possible and not include business logic; Not in repositories, because these are used for query data and not for update or inserting.
Is there a standard folder structure where another type of class for working with multiple entities(tables) should be saved? Should the business logic really be stored in the controller classes?
Symfony2 is very flexible in this regard.
You're right, entities are for one "table" only.
I would suggest you look into Services, as they are a good way to move your code from a controller to a separate class. You basically call your service and use the functions it provides. This will slim your controller down.
I am not sure what I'm doing is called ORM or Active Record Pattern.
I have an Entity base class that entities/database tables will inherit. These classes will have methods like
find
findBy
findAllBy
insert
update
delete
Getters & Setters for column data (eg. name, title, etc) via magic methods
Problem now is how do I create a database connection?
Dependency Injection - sounds complicated ...
Use a global variable, that these classes will expect to be set? - Doesnt sound right
Have a base class that Entity inherit that contain all database connection info? - doesnt sound right either
Maybe I am doing it wrong? I am open to any ideas, preferably simple for a start. I am wanting to create a simple framework for a start (not using Doctrine for example), it will give me a foundation on how such framework works. Also if its a small project, using a big framework may over-complicates things
There isnt really much thats simple about what youre attempting. Its complex thing :-)
You need to have some kind of basic entity manager and/or table class which usually holds the reference to the DB connection (or some sort of object that wraps it). All the Entity's then pass themselves to the manager when their save or delete methods are called and the manager will work out the query needed to modify the db.
You can either inject this manager, or make it a singleton and have your classes fetch it when instantiated for example.
If i were you i would check out PHP Objects Patterns and Practices by Matt Zandstra. It goes into all these patterns with some basic implementation examples.
I'd like to use the same class as a row class and a base class for getting results, but think I am doing it the wrong way...
Ie I need the same class to extend Zend_Db_Table_Row_Abstract and Zend_Db_Table_Abstract but think this is putting logic for two different things into the same class? (and extending two is impossible)..
For example, I think the base class should handle select queries etc, and the row class should handle updating etc. But I'd like to be able to go:
class Article extends BaseModel { //Set table name and some custom functions }
BaseModel { //Define custom functions for finding rows and updating }
Article::findAll() //This is table logic
Article::insert($data); //This is row login
What's the right way of doing this?
I think you are looking for the ActiveRecord pattern:
An object that wraps a row in a database table or view, encapsulates the database access, and adds domain logic on that data.
There is a proposal for a Zend_Db_ActiveRecord component, but it never left the "New" stage. There is a number of UseCases in the proposal though, which might give you some ideas how to implement that yourself. You might also be interested in using existing 3rd party solutions, like Propel or phpactiverecord
Please be aware that ActiveRecord is often misused and has a number of drawbacks due to the violation of separation of concerns due to the intermingling of db access and business logic in one class.
The right way of doing this is to have two classes - one for rows (some kind of a model) and for the table (some kind of mapper).
Why do you want to have them in one class? Isn't it the intention of classes to seperate stuff that doesn't belong together (directly)?
If you really want it to be in the same class, and a method getTable to the row-class and extend the row class to be an adapter to the table class (which I strongly dis-suggest of course :).