For example, if product is stored in more categories:
such information is stored in JSON format in CSV.
In general, in ecommerce software, we move in very complex data storage structures. The requirements for e-commerce are completely different than for some simple components. We can't just store the category number. If there are requirements for the possibility of having products in more than one category, in addition to the multidimensional field with category numbers, we also store their order, etc. And so it is for most data in e-commerce. Plus, of course, the complexity of their relational connections. Therefore, it is always easiest to use SQL directly for such complex structures.
Jan
