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.
Related
I'm new to PowerApps. I'm creating a model-driven app. I've created some custom tables in the DataVerse - Information System, and Business Process. These tables have a M:M relationship. An Information System supports one or more Business Processes and a Business Process can use one or more Information Systems. I need to capture additional attributes that describe the nature of the relationship - what role does the Information System play with respect to the Business Process, and a score indicating how effective the Information System for that Business Process.
I've learned how to create M:M relationships using the built-in functionality in PowerApps but this does not permit me to define additional attributes for the relationship.
I've created my own M:M "middle" table and created M:1 joins from that table to each of the related tables. My "middle" table contains a lookup to each of the other tables and the additional attributes I need.
I need to know how to modify the default form for each of the related tables to include the "middle" table to enable a user to select a row from the "other" table and also to supply values for the additional attributes. I have searched for several days now and have not found any literature explaining how to do this.
I'm hoping there's someone who knows how to do this or can direct me to some literature about how to do it.
Thanks in advance for any assistance you can provide.
What you did is right, initially you created a native N:N relationship and for your need it should be manual N:N relationship which you created later.
You can add the subgrid of manual N:N intersect entity (two lookups and extra attributes) in both the main entities - this way you can create related records from either side. It can be a related navigation in the form instead of subgrid as well.
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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 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/
I want to create a membership based site in Umbraco 7, following the umbraco.tv videos and reading through the docs have got me quite far.
My members will have custom properties, firstname, lastname, favourite colours, hats owned etc. I have been adding each of these as custom properties and then assigning them to the tab I want. This works fine and I can then access them from code using:
Members.GetCurrentMember().GetProperty("lastname").Value.ToString();
When I looked in my database I noticed that each of these custom properties is a row in the cmsPropertyData table, linked to the cmsMember table by the nodeId column. Is there a way I can set all of this information to store in it's own table?
Ideally, I want each Member to have a one to many relationship with favourite colours, as well as one to many relationships with other tables; each member might have 100 hats for example. What is the best way for me to set this up? Shall I create custom tables in my Umbraco database for HatsOwned and FavouriteColours, then assign each Member a unique ID so I can set my foreign keys up correctly? That way I would only need to store the Members Unique Id in the cmsPropertyTable. Is there a better way to let Umbraco deal with it? Would I have difficulty retrieving Members using either the Umbraco orm, or EF?
Any help or pointers greatly appreciated!
I would store all data in the PROFILE of the member, in the umbraco membership. E.g. timezone, hair color, ... This makes sense for other developers to find back the data.
For all other data, you have a few options:
Relationships
If you want to link nodes to members, or nodes to nodes, or... Relations link 2 umbraco entities and can be one way or two way. If you have a color node, you can link all members to this node. Just create a "favoriteColor" relationship on the developer section, linking up nodes to members. Do some programming and you are done. Don't forget that a relation is a database record linking 2 umbraco entities. So think of some caching if you use this in your front end to take off some database load. Read more on the Relationship Api in the umbraco documentation.
Content
It's pretty easy to create new nodes using code to store e.g. comments on an article. Because you are republishing the xml cache every time you create (and publish) a node, don't use content nodes for stroring your data if you have a lot of updates.
External data
It is perfectly legit to store data outside of umbraco. Just create your own tables (or content to any service you created). You could use every ORM you want to, but I would recommend PetaPoco. The reason is obvious. Umbraco uses it also. And it will make you a better Umbraco developer. There is a detailed post on stackoverflow on how to work with external data in umbraco.
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.