Mysql structure in firebase/firestore

Question

How to create a collection 1:1 and 1:n in firebase, as in the images, where I have company tables, city and categories, as would the relationship between them in the firestore, mainly the relation 1 companies has several categories.

Obs: both company and category have multiple data elements, this image is just one example.

Answer 1

The structure of both (Realtime Database and Firestore) is more or less the same, so I will respond from one but that can be used for the other. Read the documentation for more details

• Documentation Firebase Firestore
• Documentation Firebase Realtime Database

If you want to maintain the same SQL structure, basically you will use a root-level structure, for example:

{
    empresa: {
        id_empresa_1: {
            nome: 'fulano',
            categoria: {
                id_categoria_1: true,
                id_categoria_2: true
            },
            cidade: 'id_cidade_1'
        }
    },
    categoria: {
        id_categoria_1: {
            nome: 'beltrano'
        }
    },
    cidade: {
        id_cidade_1: {
            nome: 'ciclano'
        }
    }
}

"Translating" pro SQL, the objects at the root level (emrpesa, city and categories) are tables, each object within them is a row of the respective table and the keys of this object are the columns

But you can simplify company objects using a city object within the company object:

{
    empresa: {
        id_empresa_1: {
            nome: 'fulano',
            categoria: {
                id_categoria_1: true,
                id_categoria_2: true
            },
            cidade: {
                nome: 'ciclano'
            }
        }
    },
    //...
}

But this causes a nesting of the data and this should be used with caution, although simplifying the structure, it can hinder (and even disable) more complex queries