relationship between tables in Nav 2015

What if I had to use certain tables from Nav and I made those same tables in SQL( with same PKs) ?

I am not allowed to work on Nav development .

I am working on making a data warehouse based on these tables below.But I need to know the ER diagram for these.
Customer
Item
Item Ledger Entry
Location
Purch. Inv. Header
Purch. Inv. Line
Purchase Header
Purchase Line
Sales Comment Line
Sales Header
Sales Invoice Header
Sales Invoice Line
Sales Line
Sales Shipment Header
Sales Shipment Line
Salesperson/Purchaser
Ship-to Address
Planned Production Orders

Microsoft dynamics is mainly driven my the development Environment. The changes you make there are then synchronized to the SQL tables. Synchronization is the process of ensuring that the tables and their structure in Nav is the same as that in SQL.

So whats the problem with making changes in SQL? Synchronization is one way, From Nav to SQL. This effectively means that changes made on sql cannot be automatically replicated in nav. This results in SQl synchronization errors when you open the Role tailored client thus rendering the application unusable

Regards

Gideon Rono