One to many mapping in Cassandra(Ecomerce data schema) - database

Question

i am new to cassandra db and i am making simple ecommerce schema. In relational world we have following schema like
Category table (id,name),
Product table (id,categoryId,name,price,discounted_price)
so in cassandra how can i model my data if i have following queries
select all categories;
select all products;
select specific product with category name
select specific categories with their products
And if i update category name does it impact to all tables?

Answer 1

Here's a possible data model:
CREATE TABLE categories (
category_id text,
category_name text,
...
PRIMARY KEY (category_id)
)
CREATE TABLE products (
product_id text,
category_id text,
product_name text,
category_name text,
price decimal,
discounted_price decimal,
PRIMARY KEY (product_id)
)
CREATE TABLE products_by_category (
category_id text,
product_id text,
product_name text,
category_name text,
PRIMARY KEY ((category_id),product_id)
)
To get a list of categories:
SELECT category_name FROM categories
It's a full table scan which should be fine unless you have hundreds of categories.
To get a list of products:
SELECT product_name FROM products
As above, this is also a full table scan and will be problematic if you have thousands of products and/or a large cluster.
To select a specific product with the category name:
SELECT product_name, category_name FROM products WHERE product_id = ?
To get a list of products for a category:
SELECT category_name, product_name FROM products_by_category WHERE category_id = ?
Cheers!