Relations

Database Relations

Introduction

Relations are a very important part of any database. They allow you to model complex relationships between your data. For example, a User can have many Posts, and a Post can have many Comments. This is a one-to-many relationship. You can also have many-to-many relationships, where a User can have many Posts, and a Post can have many Users.

How to Use

To create a relation, you need to create a column with the Relation type. You can then select the table you want to relate to (or select same database to relate to itself). You can also select the column you want to use as the relation key as Rollup. This is the column that will be used to match the rows. For example, if you have a User table with a Name column, and a Post table with an Author column, you can use the Name column as the relation key.

Rollups

Once you create a relation, you can use the rollup function to get the related rows. For example, if you have a User table with a Name column, and a Post table with an Author column, you can use the rollup function to get all the posts for a given user.

Methods

Original value: shows the original value of the column as a list separated by commas.
Summatory: Sum all the values of a column.
Count All: Count all the values informed in a column.