# 🧙‍♂️ Adalo Database Relationships Explained

**URL:** <https://forum.adalo.com/t/adalo-database-relationships-explained/29058>\
**Category:** Resources & Tutorials\
**Created:** [July 4, 2022, 11:45am UTC](https://forum.adalo.com/t/adalo-database-relationships-explained/29058 "2022-07-04T11:45:15Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Flawless](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.adalo.com/flawless/32/20131_2.png) [@Flawless](https://forum.adalo.com/u/Flawless)\
**Post date:** [July 4, 2022, 11:45am UTC](https://forum.adalo.com/t/adalo-database-relationships-explained/29058/1 "2022-07-04T11:45:15Z")

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There are 3 types of relationship parameters that you can use for your database collections. One-to-many, many-to-one, and many-to-many. Let’s explore how each of them works.

**One-to-many relationships** are the most common type of relationship. In a one-to-many relationship, a record in one table can be linked to multiple records in another table.

**In a many-to-one relationship** , multiple records in one table can be linked to a single record in another table.

**In a many-to-many relationship** , multiple records in one table can be linked to multiple records in another table.

Creating a one-to-many automatically creates the many-to-one relationship on the 2nd collection.  
So if you create a one-to-many relationship in the user collection between Posts and Users where a user can have many posts and posts belong to 1 user, it will automatically create the relationship parameter in the posts collection of many-to-one where posts belong to 1 user and a user can have many posts.

Here are some examples of one-to-many relationships:

- A customer can have multiple orders.
- An order can have multiple items.
- A user can have multiple social media posts.
- A company can have multiple employees.
- A course can have many lessons.

Here are some examples of many-to-one relationships:

- Comments belong to a single social media post.
- Employees can be tied to one company.
- Companies can have a single owner.
- Restaurants can be put in a single category.
- Lessons belong to one course.

Here are some examples of many-to-many relationships:

- Users can block other users.
- Users can have multiple interests.
- Social media posts can have many “liked by” users.
- Tasks can be assigned to multiple users.
- Restaurants can be in many cities.

**Let’s say you want to create a “support ticket” app where you provide customer support to your customers.**

You would have a “Tickets” collection.

This collection would contain the following parameters:  
Ticket ID # (Number)  
Problem (text)  
Description (text)  
Creating User (one-to-many, a ticket belongs to 1 user, users can create many tickets)  
Ticket Replies (many-to-one, tickets can have many replies, Replies belong to 1 ticket)  
Ticket Status (one-to-many, tickets can have 1 status, Statuses can have multiple tickets)  
Ticket Category (one-to-many, tickets can have 1 category, Categories can have multiple tickets)  
Ticket Images (many-to-one, tickets can have many images, Images belong to 1 ticket)