I am creating a database for the university. In this database I want to include family relationships, but I'm not sure how to do that. I am using MySQL Workbench.
The ERD schema that I have created is as follows:
(as I'm not high enough level to post images, please click on the link below which will direct you to the image.)
ERD model for family structure
The following website has been used by me during the creation of the model:
https://do.that.ee/entity-relationship-diagram-erd-scheme-for-family-tree-database/
I would gladly receive feedback, since I'm unsure whether this is good or bad modelled.
Related
I'm not sure whether this question has already been asked in the past.
I'm writing a webcrawler, intended to extract information from multiple websites for promotions,prices and product descriptions.
Which database choice would be ideal to do an in memory comparison on the data of promotions and prices, based on identification of the same product from multiple websites.
I know the design is going to be complex for the Scraper, HTMLDataProcessor and Storage for wrangling. But, I'm looking for a solve for the data layer choice.
Appreciate the help on this.
I'd suggest first you create your object model or Entity relationship diagram for all the entities.(a.k.a ER diagram)
For instance you can see the tutorial here: http://creately.com/blog/diagrams/er-diagrams-tutorial/
Once you have the diagram and relationships between your entity then you can make a choice of whether you need relational database or not.
You need to answer question like:
Do you care about FK (foreign key) constraints?
What is the most common query and do you care about it's performance?
Is an in-memory database sufficient or do you need data to be persisted?
Think along those lines.
I'm planning to develop a web application in CakePHP that shows information in graphics and cards. I chose CakePHP because the information that we need to show is very structured, so the model approach makes easier to manage data; also I have some experience with MVC from ASP.NET and I like how simple is to use the routing.
So, my problem is that the multiple organizations that could use the app would have their own database with a different schema that the one we need. I can't just set their string connection in the app.php file because their database won't match my model.
And the organization datasource couldn't fit my model for a lot of reasons: the tables don't have the same name, the schema is different, the fields of my entity are in separated tables, maybe they have the info in different databases or also in different DBMS!
I want to know if there's a way to make an interface that achieves this
In such a way that cakephp Model/Entity can use data regardless of the source. Do you have any suggestions of how to do that? Does CakePHP have an option to make this possible? Should I use PHP with some kind of markup language like JSON or XML? Maybe MySQL has an utility to transform data from different sources into a view and I can make CakePHP use the view instead of the table?
In case you have an answer be as detailed as you can.
This other options are possible if it's impossible to make the interface:
- Usw another framework that can handle this easier and has the features I mentioned above.
- Make the organization change their database so it matches my model (I don't like this one, and probably they won't do it).
- Transfer the data in the application own database.
Additional information:
The data shown in graphics are from students in university. Any university has its own database with their own structure and applications using the db, that's why isn't that easy to change structure. I just want to make it as easy as possible to any school to configure their own db.
EDIT:
The version is CakePHP 3.2.
An important appointment is that it doesn't need all CRUD operations, only "reading". Hope that makes the solution easier.
I don't think your "question" can be answered properly, it doesn't contain enough information, not enough details. I guess there is something that will stay the same for all organizations but their data and business logic will be different. But I'll try it.
And the organization datasource couldn't fit my model for a lot of reasons: the tables don't have the same name, the schema is different, the fields of my entity are in separated tables, maybe they have the info in different databases or also in different DBMS!
Model is a whole layer, so if you have completely different table schemas your business logic, which is part of that layer, will be different as well. Simply changing the database connection alone won't help you then. The data needs to be shown in the views as well and the views must be different as well then.
So what you could try to do and what your 2nd image shows is, that you implement a layer that contains interfaces and base classes. Then create a Cake plugin for each of the organizations that uses these interfaces and base classes and write some code that will conditionally use the plugin depending on whatever criteria (guess domain or sub-domain) is checked. You will have to define the intermediate interfaces in a way that you can access any organization the same way on the API level.
And one technical thing: You can define the connection of a table object in the model layer. Any entity knows about it's origin but you should not implement business logic inside an entity nor change the connection through an entity.
EDIT: The version is CakePHP 3.2. An important appointment is that it doesn't need all CRUD operations, only "reading". Hope that makes the solution easier.
If that's true either use the CRUD plugin (yes, you can use only the R part of it) or write some code, like a class that describes the organization and will be used to create your table objects and views on the fly.
Overall it's a pretty interesting problem but IMHO to broad for a simple answer or solution that can be given here. I think this would require some discussion and analysis to find the best solution. If you're interested in consulting you can contact me, check my profile.
I found a way without coding any interface. In fact, it's using some features already included in the DBMS and CakePHP.
In the case that the schema doesn't fit the model, you can create views to match de table names and column names from the model. By definition, views work as a table so CakePHP searches for the same table name and columns and the DBMS makes the work.
I made a test with views in MySQL and it worked fine. You can also combine the data from different tables.
MySQL views
SQL Server views.
If the user uses another DBMS you just change the datasource in app.php, and make the views if it's necessary
If the data is distributed in different DBMS, CakePHP let's you set a datasource for each table, you just add it to app.php and call it in the table if it's required.
Finally, in case you just need the "reading" option, create a user with limited access to the views and only with SELECT privileges.
USING:
CakePHP 3.2
SQL SERVER 2016
MySQL5.7
I've been looking around for a while but didn't happen to come across any official name (not even an unofficial one) of a document that summarizes all the tables in the database structure including the field names and a brief description of the purpose of this field within the table.
Does such a document actually have an official or commonly used name? I made one to help myself understand the current database design of a company while designing the new one, and also made one of the new database to help others understand the new database design for the company. If this kind of document has an official name then I could have a look in a certain document to ensure mine meets the requirements for it and making maybe more informative/professional.
The document is formally called Data Dictionary.
A platform-specific example is Data Description Specifications (DDS) that allow the developer to describe data attributes in file descriptions that are external to the application program that processes the data, in the context of an IBM System
I am designing data base for inventory management system which is used by nearly 10 to 15 companies. This database contains nearly 25 tables.For designing database i'm planning to use shared schema architecture(ie each schema corresponding to a company and these all schemas are to be placed in a single database).
i want to know whether it is reliable to use shared schema architecture.
can any one please tell me is it correct decision to use above mentioned architecture.
Thanks in advance..
If I read your question, you are suggesting that each company has its own schema. This means two things:
If you decide to implement a basic change in the schema (ie not a change that one company requests), then you will have to implement this change in all the schemae.
You will probably have to implement different logic in your front
end program for each company.
Better you should develop one schema for the entire database; each table would have a field called 'CompanyID' which naturally would define to which company each row belongs. This field would be a foreign key to the Companies table.
I am trying to build a web application that enables users to refer people to the site. A user can refer up to 10 people to the site and can have up to 7 generations, meaning that each person referred to the system by a referred user will be related to the immediate referrer and the other user that referred the newly registered user’s referrer, up to the seventh level.
The diagram below will help give a view of what I mean.
I'm using SQL Server 2008 for my database.
This is impossible to answer in general because the answer depends on what kind of queries you plan to run against your data.
But there are many alternatives for how to store hierarchical data in a database. You can start with Implementing a hierarchical data structure in a database.
If that's not enough, Google is your friend