/*****Sales Posting*******/

Invoice
=======
id
invoice_no
invoice_date
customer_id
currency
exchange_rate
lead_owner_id//id of user
project_id
sales_group
payment_terms
grand_total
total_tax_amount
total_discount
round_off_amount

InvoiceItem
===========
net_amount
cost_rate
quantity
product_id

User
====
connected_employee_id
branch_id
company_id