Lesson 5 Test your knowledge

So far we created a way to track the inventory changes produced by purchase invoices. To test what you’ve learned, we advise you to create another type of invoice called sale_invoice. This invoice is similar with purchase_invoice with some differences.

To help you out, here are some tips:

• instead of supplier entity, create and use another entity called client (this one will have same properties like supplier entity);
• instead of purchase_invoice_item, create and use an entity called sale_invoice_item (similar with purchase_invoice_item);
• in the InventoryService add another method called createOut, which creates an inventory entity that contributes to the overall of the product quantity, in a way that decreases its quantity;
• create another Event listener, but this time for the sale_invoice entity;
• modify the methods of the generated workflow (called SaleInvoiceOperations) in order to keep track of inventory changes produced by this new document (sale_invoice)

The complete ER diagram shoud look like this:

erDiagram
    product {
        string name
        decimal price
        string bar_code
        int key PK "id_product"
    }

    supplier {
        string name 
        string address
        int key PK "id_supplier"
    }

    purchase_invoice {
       datetime date
       string number
       string terms
       int key PK "id_purchase_invoice"
       int id_supplier FK "id_supplier"
       int id_document FK "id_document"
    }

    purchase_invoice_item {
        decimal quantity
        decimal unit_price
        decimal amount
        int key PK "id_purchase_invoice_item"
        int id_purchase_invoice FK "id_purchase_invoice"
        int id_product FK "id_product"
    }

    document {
        int key PK "id_document"
    }

    inventory {
        decimal quantity
        string description
        int key PK "id_inventory"
        int id_product FK "id_product"
        int id_document FK "id_document"
    }

    client {
        string name 
        string address
        int key PK "id_client"
    }

      sale_invoice {
       datetime date
       string number
       string terms
       int key PK "id_sale_invoice"
       int id_customer FK "id_customer"
       int id_document FK "id_document"
    }

    sale_invoice_item {
        decimal quantity
        decimal unit_price
        decimal amount
        int key PK "id_sale_invoice_item"
        int id_sale_invoice FK "id_sale_invoice"
        int id_product FK "id_product"
    }

    purchase_invoice many--one supplier : issues
    purchase_invoice one--many purchase_invoice_item : contains
    purchase_invoice many--one document : references
    purchase_invoice_item many--one product : references

    sale_invoice one--many sale_invoice_item : contains
    sale_invoice many--one client : receives
    sale_invoice many--one document : references
    sale_invoice_item many--one product : references
    inventory many--one product : has
    inventory many--one document : generates