I've just read the Redbean Documentation, and it's awesome! But I have some questions before I proceed.
I want to create a User data structure composed in a particular way. On the site I'm working on, I have three types of users:
The professionist
The company (with a contact person to represent the company)
The student
I think the best way to implement this user data structure is to have a person table (that has all the common data), and other three tables for the professionist/company/student unique data.
A user on my site will be then a composition of Person <---> Professionist for example, but this is not a one-to-many relationship (i think).
How can I achieve this in MySQL? Or better in Redbean?
A lot of developers tend to make a butt load of tables to do what they want, and although this does work, it can get extremely complicated (especially if other developers need to do updates on your code).
What I would do is create a table called "users" and then have a row called 'type' which will allow you to assign that specific user either professionist, company or student.
so it would look something like this:
$user = R::dispense('users');
$user->name = 'Name Goes Here';
$user->type = 'Student';
R::store($user);
And you can add whatever other data you need and should be dynamic but this gives you a simplified version of what you would need.
The only other thing you can do is create a relation table that specifies the different account types, and then when you add in your user info in the "users" table just replace $user->type with $user->type_id and relate the typeid with the inserted user, but to me that just seems like more work.
Related
I'm looking to create a database for users with multi-level user rights and I don't know how to go about doing this. What I mean is that I want a manager of a business to be able to purchase my product; that person would be given Owner rights, but would also be able to grand additional users under that license--those people would be given Manager or User rights. Each level (as well as my level: Admin, and my staff: SuperUser) would obviously have individual rights/privileges).
What I'm asking, more specifically, is how to set up the database. For example, if my business is a corporate calendar/organizer, the Owner would set up departments, each with a Manager and many Users. What's the best and most efficient way to structure the database? Like, would each user (and each calendar entry) have to be associated with an ID that belongs to that specific Owner account? I'm just a little lost as to what the best way to organize the database to keep everything together, as I will have multiple different Owners with their own company structure under them.
I want to use MySQL and PHP.
I tried to make this as logical as possible. I think I'm making it too hard, but I am sure there is a standard that makes it easier....Thanks in advance.
At the very least every product/object whatsoever needs a foreign_key in its table, as for example the user's id. This is necessary and sets the relation from the product/object with the user.
And then it depends on how complex you want your system to become. An easy way would be to just use boolean columns in the user table, like an admin, an editor column and so on, with only true and false as values. In your code you could then use if and case to check if a user is an admin and show him parts of your app or not. Like a delete link for example. But you could also restrict updating and deleting to people whose user has a true value in the sufficient column.
The more complex route would include other id-fields in the tables which set a relation of something to something else. Like say you want the user to be a seller or a buyer, then you would add seller_id and buyer_id columns to the products table and check if the ids correspond with the user_id. But not "the" user_id, but a different user_id which you saved when the user created the product listing for example. This way you could guarantee, that besides your staff the user who created this thing has rights to edit it, too, because of the product's user_id being the same as his user_id (current user) when he is logged in to your system.
You could do even more complex relations but then you'd have to create another table and save other ids in it which relate certain users with say other users. In this table you save let's say a maintainer_id and a maintained_id, both have values of certain user_ids but this way you could make a relation between objects one user could change, though they belong to others. Or if you're talking of customers so the mainter_id would be allowed to write messages to those people with maintained_id, like if someone is a seller and the others are potential buyers.
I'm having a little trouble understanding exactly what you're looking for. From what I've gathered, it seems you want a database that holds permissions, users, and departments. In this very basic example I've created 3 tables. (assuming one user can only belong to one department)
You could set a foreign key in the users table which links to the primary key in the permissions table. The departments table would have the foreign key of the user_id.
You could base all of the logic on what each permission can do with your queries and application side logic.
(I can't embed images due to not having 'enough rep')
I would like to implement the classes that I made into database,
I have a class like
Class Person {
firstname ;
lastname;
email
etc
}
Class Teacher extends Person {
salary;
graduatedFrom ;
etc ...
hasMany: [classess, experiences] ;
}
Class Student extends Person{
tuitionFee ;
parentName ;
etc ...
}
I am going to use mysql database for this project,
Should I create one table named Person and store all information there
or should I create different table for each class (like Teacher, Student, etc) ?
note: i am going to implement this using YII Framework and MYSQL database.
You would be better of creating Two tables one that stores all the person details, this table would have a foreign key which references to other table which would store the role details (eg teacher, Students)
This way would be advisable with respect to scalability as well, i.e. for example tomorrow if your application has 50 roles, you wont need to create 50 tables, you just would need to add a entry in the role table.
table person would be something like this (firstname, lastname, email, role_id,etc)
role_id here is the primary key of role table
role table would be something like this (role_id,role_name,role_desc,etc)
I would create only one table Person with a column which will act as an identifier as to what the Person is (a Student, a Teacher etc...).
Advantage: we do not have to pay attention to sql joins while retrieving information as it would be fetching information from just one table! It will also give benefit when saving data. Think you do not have to save information to two different tables while storing data for Student.
In case, if you create separate table for each class ( and want to avoid sql joins) then you may end up creating lot of duplicate information in your database.
Less the number of the tables will produce a clean code.
Given the above case, it would still make sense, if you create a separate table for a special entity which you think should be stored separately (with a reference key to the main table) and do not want to clutter up the original table.
You can use a couple of different design patterns for this:
Class Table Inheritance
Concrete Table Inheritance
For more information on this (and other useful patterns) read Martin Fowler's Patterns of Enterprise Application Architecture.
For other examples:
Practical Object Oriented Models In SQL
In a StackOverflow clone, what relationship should a Comments table have to Questions and Answers?
Storing inherited objects in a database
I've done quit a bit of programming with php/mysql on small scale personal projects. However I'm working on my first commercial app that is going to allow customers or businesses to log in and perform CRUD operations. I feel like a total noob asking this question but I have never had to do this before and cannot find any relevant information on the net.
Basically, I've created this app and have a role based system set up on my data base. The problem that I'm running into is how to separate and fetch data for the relevant businesses or groups.
I can't, for example, set my queries up like this: get all records from example table where user id = user id, because that will only return data for that user and not all of the other users that are related to that business. I need a way to get all records that where created by users of a particular business.
I'm thinking that maybe the business should have an id and I should form my queries like this: get all records from example where business id = business id. But I'm not even sure if that's a good approach.
Is there a best practice or a convention for this sort data storing/fetching and grouping?
Note:Security is a huge issue here because I'm storing legal data.
Also, I'm using the latest version of laravel 4 if that's any relevance.
I would like to hear peoples thoughts on this that have encountered this sort problem before and how they designed there database and queries to only get and store data related to that particular business.
Edit: I like to read and learn but cannot find any useful information on this topic - maybe I'm not using the correct search terms. So If you know of any good links pertaining to this topic, please post them too.
If I understand correctly, a business is defined within your system as a "group of users", and your whole system references data belonging to users as opposed to data belonging to a business. You are looking to reference data that belongs to all users who belong to a particular business. In this case, the best and most extensible way to do this would be to create two more tables to contain businesses and business-user relations.
For example, consider you have the following tables:
business => Defines a business entity
id (primary)
name
Entry: id=4, name=CompanyCorp
user => Defines each user in the system
id (primary)
name
Entry: id=1, name=Geoff
Entry: id=2, name=Jane
business_user => Links a user to a particular business
user_id (primary)
business_id (primary)
Entry: user_id=1, business_id=4
Entry: user_id=2, business_id=4
Basically, the business_user table defines relationships. For example, Geoff is related to CompanyCorp, so a row exists in the table that matches their id's together. This is called a relational database model, and is an important concept to understand in the world of database development. You can even allow a user to belong to multiple different companies.
To find all the names of users and their company's name, where their company's id = 4...
SELECT `user`.`name` as `username`, `business`.`name` as `businessname` FROM `business_user` LEFT JOIN `user` ON (`user`.`id` = `business_user`.`user_id`) LEFT JOIN `business` ON (`business`.`id` = `business_user`.`business_id`) WHERE `business_user`.`business_id` = 4;
Results would be:
username businessname
-> Geoff CompanyCorp
-> Jane CompanyCorp
I hope this helps!
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Addendum regarding "cases" per your response in the comments.
You could create a new table for cases and then reference both business and user ids on separate columns in there, as the case would belong to both a user and a business, if that's all the functionality that you need.
Suppose though, exploring the idea of relational databases further, that you wanted multiple users to be assigned to a case, but you wanted one user to be elected as the "group leader", you could approach the problem as follows:
Create a table "case" to store the cases
Create a table "user_case" to store case-user relationships, just like in the business_user table.
Define the user_case table as follows:
user_case => Defines a user -> case relationship
user_id (primary)
case_id (primary)
role
Entry: user_id=1, case_id=1, role="leader"
Entry: user_id=2, case_id=1, role="subordinate"
You could even go further and define a table with definitions on what roles users can assume. Then, you might even change the user_case table to use a role_id instead which joins data from yet another role table.
It may sound like an ever-deepening schema of very small tables, but note that we've added an extra column to the user_case relational table. The bigger your application grows, the more your tables will grow laterally with more columns. Trust me, you do eventually stop adding new tables just for the sake of defining relations.
To give a brief example of how flexible this can be, with a role table, you could figure out all the roles that a given user (where user_id = 6) has by using a relatively short query like:
SELECT `role`.`name` FROM `role` RIGHT JOIN `user_case` ON (`user_case`.`role_id` = `role`.`id`) WHERE `user_case`.`user_id` = 6;
If you need more examples, please feel free to keep commenting.
In my database are 2 tables: "books" and "users". I'm displaying all the books on a page and would like the option for a user to click a little link "I've Read This", similar to Facebook's Like function with statuses. The user could click that they've read the book or unclick to "unread" the book. Other users logged in could also see who has read what. I'm questioning my approach and would like to get feedback on other directions to take for something like this.
What I had in mind was to have a field in the "users" table, maybe something like "books_read", in which I would store an array of values (book_id's). On the frontend where all the books are displayed, I would query the "books_read" field and if a value matched the current book_id, then underneath that book would be something like "User X has read this".
In short, I would store an array of "book_id"s in the "users" table to collect what books each user has read. I would pull this array and compare IDs to each book queried, and if there is a match, output that the user has read that book.
Am I missing something or maybe not looking at a cleaner approach?
In a RDBMS such as MySQL, it's rarely ever a good idea to store lists in a field, especially when you know you will be looking for specific pieces in the list later on. The database can not take advantage of an index by doing that.
Instead, you should make an additional table that links users and books read. Optionally, you could call it *users_books* and move read in to its own column.
users_booksread
-----------
user_id
book_id
Create a separate table, perhaps called book_read.
In it, for each book a user likes, store the user_id and the book_id.
Then you don't have messy arrays to deal with, everything is normalized, your design will be cleaner, and your database more flexible. Additionally, your user table won't have a bunch of extra crud bolted on to it that will affect performance in unfortunate ways.
I have a site that scrapes all the episodes from tv.com from certain series.
So my database has a User table, a Show table, an Episode table, a Show_User table (to associate shows with users, HABTM), an Episode_Show table (to associate episodes with shows, HABTM), a Episode_User table (to associate episodes with shows, only as a way of marking them as 'watched').
Now I want to add a way of marking an episode as 'downloaded' too.
So at the moment, the Episode_User table has two fields, Episode_Id and User_Id. Should I create a new table entirely for this? Or just add a field to the Episode_User table?
I'm using CakePHP's automagic features, and don't particularly want to break it. But if I have to, I have to...
Thanks for any advice.
I don't see why you would want to create a new table for episodes a user has downloaded. To me it would make the most sense to modify the Episode_User table to have a field for watched and a field for downloaded, since it's all relating back to the same pair of entities, users and episodes.
However, any time I've stored information about a relationship between two tables in that manner, I've found that regardless of the framework I'm using, the ORM inevitably become more complicated, but I don't think there's any way around there.
With CakePHP for handling those kinds of complicated situations, read up about the model behavior, Containable. It's not very well documented in the CakePHP book, but is really quite useful in a situation where you need to use the fields in Episode_User, for example, if you needed to find all of the users that had watched a particular episode, but not downloaded it.
Also, it occurred to me, while reading your post, that you could possibly make your data model more simple by having a hasMany relationship between shows and episodes. An episode will never belong to more than one show, so your episodes table could just have another field, show_id, which related back to the show table, and you wouldn't even need the Episode_Show table.