I'm in middle of creating a social networking site something like facebook, and got struck up with database schema design for it.. from previous questions i posted here, i confirmed that i cant create new database or tables for a new user who registers onto my site. I need to insert new row [thats my only option(correct me if i'm wrong!)]. but, this works out for registration for the first time. what if the user posts something new on his profile.. where should i insert this update.. coz, i cant insert them into rows as dey correspond to each user.. and too many columns cannot be created.. what is the solution for this.?
schema =>
TableName : User_content
userId Name College City Status_Updates Messages
1 a sfd fds fsds sdds
2 f dfg dfd fdf dfd
what if user 1 updates something.. what i need to do nw. Think its a status update, how to go about it.?
Before you start thinking about this social network site you dream if
Developing you need to understand database modelling fundamentals. This link will help you with some simple concepts. http://www.databaseanswers.org/tutorial4_data_modelling/index.htm
Add tables based on what you want to allow your users to do and the related data you need to store as a result. Some example tables:
'user_account': User account information (e-mail address, password) - referenced by user ID
'user_profile': Basic user profile information - referenced by user ID
'user_status': User status message - referenced by user ID
I have the sense that this is your first major database application, and if so, you need to learn more about database design in general before you take on creating an application like this. There are many things to consider when designing a database schema and designing it well from the start is key. The core of your application will rely on how well your data is organized and accessible, so ensure you spend enough time developing a good design.
Good luck!
Related
I am a developer and have never worked on DB before (designing a DB). I am designing a database for an employee management system which is a Node.js + Express application using MySQL as its DB.
I already have the required tables, columns sorted out but there are still few unknowns I am dealing with. This is my plan so far and I need your input on it.
The end users using this application will be small - mid size companies. The companies won't be sharing the tables in the database. So if there is a table named EmployeeCases I plan to create a new EmployeeCases table for each existing company or a new one who signs up for this application. I am planning to name the table as EmployeeCases_989809890 , where "989809890" will be the company id (or customer id). So if we have 3-4 companies who signed up for us, then all the tables (at least the ones which a company uses) will be recreated and named as TableName_CompanyId. My questions, is this a good way to go? Is there a better way?
All the employee's data is held by the Employee table, including their login and password. Now each Employee table in DB will be named as Employee_CompanyId (as per my plan above). My question is, when an employee logs in, how will I know which Employee table to query to? Or should I remove the login from the Employee table and create a universal Users table where all the employees will be stored? The Users table will also have the CompanyId as one of its column and I will read the CompanyId from there which will be used to query other tables.
Any reference, website or blogs on this type of design will be appreciated.
Thanks.
I don't recommend this approach, I think you should either:
A) Put all the information in the same tables and have a companyId column to sort them out
OR
B) Have separate databases for each company and use the appropriate database using the code.
The thing is, with your approach, you'll have a hard time maintaining your application if you have multiple copies of the same table with different names. If you decide to add a column to one of the tables, for instance, you will have to write as many SQL scripts as you have table instances. You'll also have a bad time with all of your unique identifiers.
Here are some advantages/disadvantages of each design:
A) Put all the information in the same tables and have a compagnyId column to sort them out
Advantages:
Simplest
Allow usage of foreign key / constraints
Great for cross / client data extraction
Disadvantages:
Not portable (a client can't just leave with his/her data)
Can be perceived as less secure (I guess you can make the case both ways)
More likely to have huge tables
Does not scale very well
B) Have separate databases for each company and use the appropriate database using the code.
Advantages:
Portable
Can be perceived as more secure
Disadvantages:
Needs more discipline to keep track of all the databases
Needs a good segregation of what's part of your HUB (Your application that tracks which client access which database) and that's part of your client's database.
You need a login page by company (or have your clients specify the company in a field)
An example of an application that uses this "two-step login" is Slack, when you sign-in you first enter your team domain THEN your user credentials.
I think Google Apps for Work as the same approach. Also, I think most CRM I worked with has a separate database for their clients.
Lastly, I'd like to direct you to this other question on stackoverflow that links to an interesting example.
You shouldn't split your tables just because companies won't share their information. Instead, you should have a companyId column in each table and access to the relevant data for each query. This should be implemented in your backend
I use access to store concert registration information at the non-profit I currently work at. I have it set up so that I dump all of the patron contact information into one table, and all of the concert registration information into another. when we change our concert season, I simply copy/paste the "2012-13 concert registration table" and rename it the "2013-14" concert registration table".
the concert registration table serves as my "hub" for all my other information. I have about a half-dozen summary queries that show information for specific concerts, who I still need to collect payment for etc. as well as many Word mail merges associated with each document. This setup works great, except that every season I need to go in and re-link all of the queries and word docs to the new registration table
I will be leaving my job at the end of next month, and I would like to make the database more user-friendly, especially since I am fairly certain that my replacement will have zero familiarity with access. my questions are:
1) Is there a more elegant, easy way to transition from season to season other than to create a new registration table and subsequent queries from year-to-year?
2) How can I idiot-proof this database for the new person when I'm gone? I'm scared that if I create an extensive "how-to" guide, it simply won't be read and the person will be forced to reinvent the wheel. I'm toying with creating a switchboard, but I'm scared that this will make the database seem more unapproachable.
Thank you for your insight, happy to clarify if there are any questions!
Just make 1 table. Call it "registration table" and add a new field called Season. Your queries will be include a filter for that field. Then you won't need to relink your queries, copy tables, etc.
For an example, say you have a query to pull all the information from that table for a particular season. It might look something like:
Select * from RegistrationTable where Season=[What Season];
When run, the query will prompt the user for the season and pull only that data.
Also, I do recommend the "how-to" guide. There's probably a lot of manual manipulation of the database that you do and don't even think about. And if nothing else, you can always say you gave them documentation and thus provided for your successor.
So I have this application that I'm drawing up and I start to think about my users. Well, My initial thought was to create a table for each group type. I've been thinking this over though and I'm not sure that this is the best way.
Example:
// Users
Users [id, name, email, age, etc]
// User Groups
Player [id, years playing, etc]
Ref [id, certified, etc]
Manufacturer Rep [id, years employed, etc]
So everyone would be making an account, but each user would have a different group. They can also be in multiple different groups. Each group has it's own list of different columns. So what is the best way to do this? Lets say I have 5 groups. Do I need 8 tables + a relational table connecting each one to the user table?
I just want to be sure that this is the best way to organize it before I build it.
Edit:
A player would have columns regarding the gear that they use to play, the teams they've played with, events they've gone to.
A ref would have info regarding the certifications they have and the events they've reffed.
Manufacturer reps would have info regarding their position within the company they rep.
A parent would have information regarding how long they've been involved with the sport, perhaps relations with the users they are parent of.
Just as an example.
Edit 2:
**Player Table
id
user id
started date
stopped date
rank
**Ref Table
id
user id
started date
stopped date
is certified
certified by
verified
**Photographer / Videographer / News Reporter Table
id
user id
started date
stopped date
worked under name
website / channel link
about
verified
**Tournament / Big Game Rep Table
id
user id
started date
stopped date
position
tourney id
verified
**Store / Field / Manufacturer Rep Table
id
user id
started date
stopped date
position
store / field / man. id
verified
This is what I planned out so far. I'm still new to this so I could be doing it completely wrong. And it's only five groups. It was more until I condensed it some.
Although I find it weird having so many entities which are different from each other, but I will ignore this and get to the question.
It depends on the group criteria you need, in the case you described where each group has its own columns and information I guess your design is a good one, especially if you need the information in a readable form in the database. If you need all groups in a single table you will have to save the group relevant information in a kind of object, either a blob, XML string or any other form, but then you will lose the ability to filter on these criteria using the database.
In a relational Database I would do it using the design you described.
The design of your tables greatly depends on the requirements of your software.
E.g. your description of users led me in a wrong direction, I was at first thinking about a "normal" user of a software. Basically name, login-information and stuff like that. This I would never split over different tables as it really makes tasks like login, session handling, ... really complicated.
Another point which surprised me, was that you want to store the equipment in columns of those user's tables. Usually the relationship between a person and his equipment is not 1 to 1 and in most cases the amount of different equipment varies. Thus you usually have a relationship between users and their equipment (1:n). Thus you would design an equipment table and there refer to the owner's user id.
But after you have an idea of which data you have in your application and which relationships exist between your data, the design of the tables and so on is rather straitforward.
The good news is, that your data model and database design will develop over time. Try to start with a basic model, covering the majority of your use cases. Then slowly add more use cases / aspects.
As long as you are in the stage of planning and early implementation phasis, it is rather easy to change your database design.
I am working on one portal where will be few user roles. I have been wondering what is the best way to handle them. I have created separated tables for users and clients, but clients will want the functionality as users and users can become clients easy too.
I also don't want to make many joints, so what I as thinking is this:
I will have 4 different user roles (at least for now) as follow:
user
client
reviewer
admin
I will assing "id" to each role. At the same time I will keep table in mysql with these roles. It will be something like:
1 - admin
2 - reviewer
3 - client
4 - user
This table will be used only upon creation of user, to get the code of user "permissions". So Let's say that there will be a guy who is a user and reviewer. His role would be 24.
login password email role created
----------------------------------------------------------
guy password guy#gmail.com 24 2012-12-08 23:12:30
I think this could work pretty well, but still want to ask if you guys think this is good and effective solution.
Thanks
The other way to do this would be to have a many to many USER_ROLE table where for your example guy would have the following entires.
login role
guy 2
guy 4
I generally prefer this method of tracking roles. A join against this table in a situation like this should be fast and painless, especially if you move to using a user_id instead of a login, and index appropriately.
What you're defining is a Role Based Access Control System (I would suggest looking up resources on this). An RBAC system will have a separate table for users and another table for roles. There will be a many to many relationship between users and roles. Also, you will connect a permissions table to roles in another many to many relationship. The image attached represents how to implement this system:RBAC SYSTEM IN MYSQL
A similar question was asked before: How to design a hierarchical role based access control system
currently Im working on a project that, at first glance, will require many tables in a database. Most of the tables are fairly straightforward however I do have an issue. One of the tables will be a list of members for the website, things like username, password, contact info, bio, education, etc will be included. This is a simple design, however, there is also a need for each member to have their availability entered and store in the database as well. Availability is defined as a date and time range. Like available on 4/5/2011 from 1pm to 6pm EST, or NOT available every friday after 8pm EST. For a single user, this could be a table on its own, but for many users, Im not sure how to go about organizing the data in a manageable fashion. First thought would be to have code to create a table for each user, but that could mean alot of tables in the database in addition to the few I have for other site functions. Logically i could use the username appended to Avail_ or something for the table name ie: Avail_UserBob and then query that as needed. But im curious if anyone can think of a better option than having the potential of hundreds of tables in a single database.
edit
So general agreement would be to have a table for members, unique key being ID for instance. Then have a second table for availability (date, start time, end time, boolean for available or not, and id of member this applies to). Django might sound nice and work well, but i dont have the time to spend learning another framework while working on this project. The 2 table method seems plausable but Im worried about the extra coding required for features that will utilize the availability times to A) build a calender like page to add, edit, or remove entered values, and B) match availabilities with entries from another table that lists games. While I might have more coding, I can live with that as long as the database is sound, functional, and not so messy. Thanks for the input guys.
Not to sound like a troll, but you should take a look into using a web framework to build most of this for you. I'd suggest taking a look at Django. With it you can define the type of fields you wish to store (and how they relate) and Django builds all the SQL statements to make it so. You get a nice admin interface for free so staff can login and add/edit/etc.
You also don't have to worry about building the login/auth/change password, etc. forms. all that session stuff is taken care of by Django. You get to focus on what makes your project/app unique.
And it allow you to build your project really, really fast.
djangoproject.org
I don't have any other framework suggestions that meet your needs. I do... but I think Django will fit the bill.
Create a table to store users. Use its primary key as foreign key in other tables.
The databases are written to hold many many rows in a table. There are not optimized for table creation. So it is not a good idea to create a new table for each user. Instead give each user an unique identifier and put the availability in a separate table. Provide an additional flag to make an entry valid or invalid.
Create a table of users; then create a table of availabilities per user. Don't try to cram availabilities into the user table: that will guarantee giant grief for you later on; and you'll find you have to create an availabilities table then.
Google database normalization to get an idea why.
Take it as truth from one who has suffered such self-inflicted grief :-)