# Category

We can take the user structure as a reference to compose the category one. So, we can copy and paste the contents of both user's **CreateDTO** and **Service** files to the corresponding category's files, and after that adjust where necessary.

> The **CTRL + F** hotkey can be used to quickly swap words, for example when copying service's contents, swap **user** for **category**. The option **Preserve Case** may also be helpful.

Let's load the related products in the <mark style="color:blue;">`findOne()`</mark> method, which may make sense as a business rule. Also, in the <mark style="color:blue;">`remove()`</mark> method, make sure there are no related products.

```typescript
if (category.products.length) {
  throw new ConflictException('Category has related products');
}
```

<mark style="color:green;">**Commit**</mark> - Implementing category logic and prohibiting exclusions that cause orphans


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