The following is an E-R diagram of the multi-table connections for the in-out stock business in the back-end of a consumer goods distributor. Please answer the following questions based on the multi-table connection relationships in the diagram:

销售表: sales table
库存表: storage table
采购进货单明细: purchase order details table
产品表: product table
客户表: customer table
品牌表: brand table
采购进货单: purchase orders table
The connection pattern formed by the sales table, inventory table, purchase order detail table, and product table is: