= Entity Sets

- Company(company_id, name, address, vat, email, created_at, updated_at)

- User(user_id, name, email, password, role, company_id)
    *Reference: company_id → Company(company_id)

- Employee(employee_id, name, email, status, iban, cv, photo, notes, project, company_id)
    *Reference: company_id → Company(company_id)

- Candidate(candidate_id, name, email, status, cv, interview_stage, notes, company_id)
    *Reference: company_id → Company(company_id)

- Client(client_id, name, representative, email, phone, address, vat, logo, company_id)
    *Reference: company_id → Company(company_id)

- Invoice(invoice_id, from, to, issue_date, due_date, notes, status, company_id, client_id)
    *References:
company_id → Company(company_id)
client_id → Client(client_id)

- LineItem(line_item_id, description, quantity, unit_price, currency, total, invoice_id)
    Reference: invoice_id → Invoice(invoice_id)

- EmailTemplate(template_id, type, subject, body, company_id)
    *Reference: company_id → Company(company_id)

= Relationship Sets Between Entities

- Employee_Belongs_To_Company(employee_id, company_id)
    References:
employee_id → Employee(employee_id)
company_id → Company(company_id)

- Candidate_Belongs_To_Company(candidate_id, company_id)
    References:
candidate_id → Candidate(candidate_id)
company_id → Company(company_id)

- Client_Belongs_To_Company(client_id, company_id)
    References:
client_id → Client(client_id)
company_id → Company(company_id)

- Invoice_Belongs_To_Client(invoice_id, client_id)
    References:
invoice_id → Invoice(invoice_id)
client_id → Client(client_id)

- Invoice_Belongs_To_Company(invoice_id, company_id)
    References:
invoice_id → Invoice(invoice_id)
company_id → Company(company_id)

- LineItem_Belongs_To_Invoice(line_item_id, invoice_id)
    References:
line_item_id → LineItem(line_item_id)
invoice_id → Invoice(invoice_id)

- User_Belongs_To_Company(user_id, company_id)
    References:
user_id → User(user_id)
company_id → Company(company_id)

- EmailTemplate_Belongs_To_Company(template_id, company_id)
    References:
template_id → EmailTemplate(template_id)
company_id → Company(company_id)