Are you good at using relations and rollups?
In a previous article, we introduced the essential properties for Notion beginners, "Basic Edition."
This time, as an "Intermediate Edition," we will explain "relations" and "rollups," which are common stumbling blocks when you're getting used to Notion!
Both are key features for mastering Notion, so please try to master them.
🎬 Director：Rei
✍🏻 Writer：Mino Kurumi
1. What is a relation?
Notion's relations are a feature that links separate databases.
By creating relations, you can link pages from separate databases using properties.
We explain "databases" and "properties" in detail here!
When you link databases, you can select pages from the linked databases using properties, like this.
1-1. Use cases for relations
It might be easier to understand if you know where to use them, so here are some examples of how relations can be used.
✍🏻 Case 1: Project management
I want to link two databases, "Project List" and "Task List," using relations.
🔼 On the "Project List" side...
By selecting tasks for a project using relations, you can see a list of tasks for that project.
🔽 On the "Task List" side...
You can see which project each task belongs to.
Furthermore, with relations, you can filter and display tasks by project.
✍️Case 2: Recipe management
I want to link two databases, "Recipes" and "Shopping List," to create a shopping list for this week.
🔼 On the "Recipe" side...
Relate the necessary ingredients for that recipe.
🔽 On the "Shopping List" side...
You can see a list of ingredients needed for the recipes registered in your meal plan.
In addition, it can be usefully applied in situations where you "want to keep databases separate but manage them in a linked way."
It's recommended to just try using it and get a feel for it when you encounter a situation where it's needed.
1-2. How to use relations
Here's how to set up relations:
1. Click the "+" button on the right end of the database.
2. Select "Relation."
3. Select the database you want to link as the relation target.
4. Turning on "Show on DB_〇〇" creates a two-way relation (*), and a property is added to the related database.
5. Click "Add relation."
* What is a two-way relation?
When "Show on DB_〇〇" is turned on, the relation appears in both linked databases. If it's one-way, it will not appear in the target database (in this case, the Project List).
2. What is a rollup?
Another feature I'd like to introduce is "rollup," which can be used in conjunction with relations.
Rollup is a feature that allows you to retrieve and display properties from a linked database, or to display their calculated results.
For example, when creating a household budget like this, you can use rollup to display the total expenses for each category entered in the top table as a total amount in the "January" section of the bottom table.
The only thing to note is that rollups cannot be used without relations.
2-1. Rollup use cases
✍️Case 1: Household budget
If you want to display the total monthly expenditure for each category entered in the "Income/Expenditure Entry" as a total in the "Monthly Income/Expenditure" using a rollup.
🔼 On the "Income/Expenditure Entry" side...
Enter the amount for each category and link it to the corresponding month's page in "Monthly Income/Expenditure" (e.g., "January" for January) using a relation.
🔽 On the "Monthly Income/Expenditure" side...
Relate all categories for the relevant month and calculate the total expenditure using a rollup.
While I've used numerical values as an example here, you can, of course, also pull and display other properties such as tags and assignees.
2-2. How to use rollups
Here's how to set up rollups:
1. Link databases using relations.
2. Select "Rollup" from the "+" button on the right end of the database.
3. In "Relation," select the database you just linked.
4. In "Property," select the property you want to display in this database.
5. In "Calculate," choose the display format.
You can display the original format, as well as totals, percentages, and more.
Summary
That concludes the explanation of relations and rollups!
These two features are essential hurdles when using Notion, but understanding them will make Notion even more enjoyable. Please try playing around with them on your own page to get a feel for them!
All the use cases introduced in the article are available as templates! You can find the templates here.
The ultimate task management template realized with Notion, "Todotion," is available here!
Our two-hour "Notion Master Course" is now available, teaching you Notion from scratch through videos!
Our book "Notion Life Hacks," which introduces 36 ways to use Notion, is also now on sale!
