In our app few of our Eloquent models need only a specific columns always. What is the right way to have my method? As of now there is a new method written which does,
DB::table('MyTable')->selectRaw('required_column_list')
I feel it is odd since the table name is hard-coded. What is the right way to do?
If you don't want to hard-code table name, so you have to hard code ModelName?
Use model name with getTable function
DB::table(YourModel::create()->getTable());
Related
I am rather stuck (or not stuck, as I could go and solve this simply with foreach) with a problem I am facing.
I have database where I have a model that should have a relation to another one. No problem here. However, that relation is defined in a column that is an array. I sadly cant change that. Is there any way to still get the corresponding relation of hasMany etc?
Or is my only choice to get all entries of my model and then go over foreach?
Thanks in advance.
I have a Laravel 8 application and am wondering how to solve the problem of how to solve a typical polymorphic issue. I have an Employee model. That Employee can be an ExecutiveEmployee or EntryLevelEmployee. There will be methods an ExecutiveEmployee has that an EntryLevelEmployee doesn't have and the inverse is also true.
Using Laravel 8, is it right to create a base Employee model (without a corresponding table?) and then create two models named ExecutiveEmployee and EntryLevelEmployee that inherit from Employee? This would also imply that both employee types will have two different database tables, even though there will be a lot of overlapping data.
Does it make sense to just have one Employee model and create a migration that has the employee type listed in the model? I am assuming that it's ok if an EntryLevelEmployee has some database attributes which are relevant to it that may or may not be relevant to an ExecutiveEmployee type here, or is that an incorrect assumption?
What's the correct way to model this in Laravel 8? I prefer to keep everything in one table because of how similar the models are. I do have to keep in mind that there will be data that one has that the other doesn't. There will be different accessor methods as well.
Is it possible to have everything in one employees table while utilizing multiple models? Meaning, if I create two models named ExecutiveEmployee and EntryLevelEmployee they would both query the underlying table employees?
UPDATE 1
The more I research, the more I think polymorphism is the incorrect approach here and what I might need is Single-Table Inheritance. This package seems to bring the capability to Eloquent. Would there be a good reason to not use this?
I would use polymorphic relationships in this case, because you are more flexible and have less coupling.
Using the Single Table Inheritance (STI), you can add type specific columns in the employees table and make them nullable. But think about adding/removing types in the future.
executive_employees
id - integer
executive_specific - string
entry_level_employees
id - integer
entry_level_specific - string
employees
id - integer
name - string
email - string
employable_id - integer
employable_type - string
As for the STI the same would be
employees
id - integer
name - string
email - string
type - string
executive_specific - nullable string
entry_level_specific - nullable string
So STI would be suitable when you don't have type specific columns. But you want to add specific behavior in your code. For example a User type (Admin, Author).
Even so, it's a matter of preferences.
It really depends on the state and behavior of your employee object.
Below are few points I will consider to make a decision
If your objects' states/properties are different then definitely you will create different models as your data will be stored in different tables.
If most states/properties are same and some are different, you can
consider storing all in one table/model and for the difference in
behavior create separate table like Ron Van Der Heijden has
suggested and you can consider query scope with that to make
transaction with database.
And another view will be
How many JOINs you will create if you will create different tables,
will that impact the performance and other stuffs, will it make your
code complex?
Can you make simpler relations and handle stuffs independently?
When you are making an API, will your
code make the api overworking? or you need to create too many request
for any operation?
These stuffs will decide how you will make a decision.
Update 1:
Another point I would like to add about the package you are thinking to use, consider using a parent key in table and you can define relationships in a single model.I do not think you need to use a package, you can define it yourself, I guess.
I don't understand why you don't create a simple one-to-many relation. Based on the information you provided, the polymorphic relation looks unnecessary. I think the right way is to create employee_roles table and relations. Then you can give different permissions to different employee types. There are several ways to do that. You can create a middleware to create route restrictions. You can check the role before executing a function in the controller, and run only if the employee has permission. You can use if-else in blade not to render the parts that can't be used by auth user etc.
If you have different “types” of employees, and each employee type should have different logic then yeah, that sounds like a polymorphic relationship.
I have a doub about Laravel. The models are used to define the relationships between the models like hasMany, belongsTo, etc. Also the models are used to define the fillable fields. But he models are only for that? Because I already check some examples that it seems that some queries are executed in the models instead of the controller so Im not understanding if the models should also have the querying of the relationships or not. Can you give a help to understand better what is the correct use of models (what should be placed in the models)?
Its same way to execute queries on model or controller. Written queries in model make your controller more clean. We can write mutator, accessor or query scope in eloquent model. Correct me if I'm wrong.
Visit https://laravel.com/api/5.5/Illuminate/Database/Eloquent/Model.html
You can refer this documentation, it's quite helpful if you want to know deep basics and responsibilities about particular part in Laravel.
Models are mostly used to make an outlook of the data i.e what fields are going to be saved in the database and we also use it to associate the relationships with other related data as you already know but we also use it to alter the values that are either going in/out of the data base which you can check in the documentation in link bellow https://laravel.com/docs/5.6/eloquent-mutators
the main purpose is to divide the code between controller and model (were it best fit to be)
I am just learning Yii, and I am able to create ActiveRecord models which map to the database tables.
Is there such a thing as a viewmodel implementation in Yii as I can't find any kind of documentation. Maybe it's called something else?
Example:
I have a product table and a category table of which I wish to expose the following columns in the viewmodel.
product.id
category.name
product.name
product.price
I am aware that I can do this by referring to the fields as such individually within Yii, however the above is a cleaner / simpler version of my real much more complex database.
As such, a ViewModel functionality whereby I can expose the columns which I want to, and then re-use it wherever I need to without repeating code would be quite handy.
Yii1 doesn't have a view model per se, although it's coming in Yii2. Instead, pass your values as parameters to your render method in your controller and refer to them by name in your view ...
I am working on a MVC3 code first web application and after I showed the first version to my bosses, they suggested they will need a 'spare' (spare like in something that's not yet defined and we will use it just in case we will need it) attribute in the Employee model.
My intention is to find a way to give them the ability to add as many attributes to the models as they will need. Obviously I don't want them to get their hands on the code and modify it, then deploy it again (I know I didn't mention about the database, that will be another problem). I want a solution that has the ability to add new attributes 'on the fly'.
Do any of you had similar requests and if you had what solution did you find/implement?
I haven't had such a request, but I can imagine a way to get what you want.
I assume you use the Entity Framework, because of your tag.
Let's say we have a class Employee that we want to be extendable. We can give this class a dictionary of strings where the key-type is string, too. Then you can easily add more properties to every employee.
For saving this structure to the database you would need two tables. One that holds the employees and one that holds the properties. Where the properties-table has a foreign-key targeting the employee-table.
Or as suggested in this Q&A (EF Code First - Map Dictionary or custom type as an nvarchar): you can save the contents of the dictionary as XML in one column of the employee table.
This is only one suggestion and it would be nice to know how you solved this.