Robust Inventory SQL Database Build

I need a well-structured relational database that puts inventory management at the centre while also retaining rich customer data. To keep everything normalised I expect the design to grow beyond seven tables, separating stock items, stock movements, suppliers, purchase orders, sales orders, customers, support tickets and their related histories.

The customer side must capture three key areas: personal details (name, address, phone number), purchase history, and customer support interactions. These entities need to tie back cleanly to products and transactions so I can run straightforward queries such as “items bought by customers who later opened a ticket on those items”.

Deliverables
• An ER diagram showing every table, primary/foreign key, and relationship
• A clean, commented SQL DDL script (MySQL or PostgreSQL preferred) that creates the schema exactly as diagrammed, including indexes and referential integrity constraints
• A brief set of sample INSERT statements so I can test joins and reports immediately

Acceptance criteria
1. All tables follow 3NF or better.
2. No orphan records possible thanks to foreign-key rules.
3. A sample query returns the end-to-end flow: customer → purchase → inventory deduction → support ticket.

Once the script loads without errors and the sample queries produce correct results the project is complete.