I am trying to achieve one to many relationship. I know how to do basic one to many relationship between requestor id and userid.
My question is How to refer gtlUserId(resourceRequestTable) to gtlUserId (User table) as by default spring is mapping gtlUserId (resourceRequestTable) to userId in user table
It has some Ways.
I think you should give a specific way during all project !
As My experience each many to one must be a Drop Down in Client side .
However in your Table ResourceTypeEntity should be drop down inside ResourceRequesTable when value of option is Id[primary Key].
Also Your table not seems good design why two many to one map to same table? it may cause 3NF problem in DB also pay attention Cascade it when Parent Table related to other Parent is not good Design ,Keep it simple with uni Direction Many to One And force user to delete manually parent is better ,CaseCade Delete when Parent has related to other table will make exception handling and testing too hard.
please take a look https://examples.javacodegeeks.com/enterprise-java/spring/mvc/spring-mvc-dropdown-box-example/
Related
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 did some searching but couldn’t find a good solution for my problem. Anyway, I am really new to Laravel and this is my first project, I appreciate your help.
In my project, these is staffs table in database which holds the records for four types of staff (Staff, Manager, SalePersonnel and Secretary) and each of these three types have special attributes . However, storing all type of stuff in one table results a lot of NULLS.
I want to separate the staffs table into four tables, one parent table that has common attributes of all staff and three more table for each type of staff.
How can I do this in Laravel context? How to create a parent record and child record. Please provide a detailed answer.
Sorry for being that dumb, as I said I am new to Laravel.
I have two scenarios that I want to support but I don’t know the best way to design relations in the elasticsearch. I read the entire elasticsearch documentation but I couldn’t find the best way to design types for my scenarios.
Multiple one to many.
Let’s assume that I have the following tables in my relational database that I want to transfer to the elasticsearch:
Transaction table Id User1Id User2Id ….
User table Id Name
Transaction contains two references to User. As far as I know I cannot use the parent->child relation specifying two parents? I need to store transaction and user in separate types because they can be changed separately. I need to be able to search transaction through user details and return users connected with transactions. Any idea how to design such structure in the elastic search?
Many to many
Let’s assume that we have the following tables:
Order Id …
OrderLine OrderId UserId Amount …
User Id Name
Order line is always saved with the order so I thought that I can store order with order lines as a nested object relation but the user must be in the separate table. Is there any way how can I connected multiple users from order line with user type? I assume that I can use application side join but I need to retrieve order and order line always together and be able to search order by user data.
I can use grandparent and grandchildren relations but then I need to make joins in the application. Any idea how to design it in the best way?
I would like to provide users with points when they do a certain thing. For example:
adding article
adding question
answering question
liking article
etc.
Some of them can have conditions like there are only points for first 3 articles a day, but I think I will handle this directly in my code base.
The problem is what would be a good database design to handle this? I think of 3 tables.
user_activities - in this table I will store event types (I use
laravel so it would probably be the event class name) and points for
specific event.
activity_user - pivot table between user_activities and users.
and of course users table
It is very simple so I am worrying that there are some conditions I haven't thought of, and it would come and bite me in the future.
I think you'll need a forth table that is simply "activities" that is simply a list of the kinds of activities to track. This will have an ID column, and then in your user_activities table include an 'activity_id' to link to that. You'll no doubt have unique information for each kind, for example an activities table may have columns like
ID : unique ID per laravel
ACTIVITY_CODE : short code to use as part of application/business logic
ACTIVITY_NAME : longer name that is for display name like "answered a question"
EVENT : what does the user have to do to trigger the activity award
POINT_VALUE: how many points for this event
etc
If you think that points may change in the future (eg. to encourage certain user activities) then you'll want to track the actual point awarded at the time in the user activities table, or some way to track what the points were at any one time.
While I'm suggesting fourth table, what you really need is more carefully worded list of features to be implemented before doing any design work. My example of allowing for points awarded to change over time is such a feature that you don't mention but you'll need to design for if this feature is needed.
Well I have found this https://laracasts.com/lessons/build-an-activity-feed-in-laravel as very good solution. Hope it helps someone :)
I'm developing a ADF Fusion Web Application and have some problems with EntityAssociations and ViewLinks.
I have a database table Project with id, name etc. Also I have a table Technology which only contains a id and the name of the technology, for example "ADF".
The relationship between theese two entities is many-to-many. Means one project can have multiple technologies assigned and inverse a technology can be assigned to multiple projects.
This relationship is described trough a join table named Project_Technology. Columns of this table are Project_FK, Technology_FK and Effort. Project_FK and Technology_FK are a composite primary key, Effort is an additional attribute.
Can someone explain me how to map EntityObject and ViewObjects that I can access the Effort, too? "Regular" many-to-many associations aren't that hard to implement but I am really struggling with the additional attribute.
Any help is appreciated. Thanks in advance!
Edit:
I could solve my issues. See answer below for details.
I got it working.
The Problem was the composite primary key on my join tables. It seems like ADF doesn't like them. I put a extra column ID on the join tables and now I can insert values by using the CreateInsert Data Controls.