this post was submitted on 16 Jun 2024
39 points (93.3% liked)

Programming

17313 readers
398 users here now

Welcome to the main community in programming.dev! Feel free to post anything relating to programming here!

Cross posting is strongly encouraged in the instance. If you feel your post or another person's post makes sense in another community cross post into it.

Hope you enjoy the instance!

Rules

Rules

  • Follow the programming.dev instance rules
  • Keep content related to programming in some way
  • If you're posting long videos try to add in some form of tldr for those who don't want to watch videos

Wormhole

Follow the wormhole through a path of communities [email protected]

founded 1 year ago
MODERATORS
[email protected]
[email protected]
[email protected]
39
understanding many2one, one2many and many2many relationshit (lemmy.ca)
submitted 5 months ago by [email protected] to c/[email protected]
11 comments fedilink hide all child comments
 

Hii,

I am new to database thing so I am trying to wrap my head around it.

  1. many2one: so in this relationship you will have more than one record in one table which matches to only one record in another table. something like A <-- B. where (<--) is foreign key relationship. so B will have a column which will be mapped to more than one record of A.

  2. one2many: same as many2one but instead now the foreign key constrain will look something like A --> B.

  3. many2many: this one is interesting because this relationship doesn't make use of foreign key directly. to have this relationship between A and B you have to make a third database something like AB_rel. AB_rel will hold values of primary key of A and also primary key of B. so that way we can map those two using AB_rel table.

tell me if I got something wrong :) give me some suggestion <3

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 1 points 5 months ago

I am familiar with NoSQL databases. they are generally easy to use and don't require much effort. however we use postgresql where I am doing my internship. It's a Odoo based company and Odoo uses postgresql as backed database.