I want to import products to Odoo 12 Community Edition from CSV or Excel file. But I want a template (csv or excel) file from Odoo that I will fill and import in Odoo?
From where I can take those template files from Odoo for Products, Customers, Vendors etc.
And If we have more fields that are not available in Odoo standard tables:
1) Should we add directly into Odoo standard tables with x_ prefix
2) Or to create new module with inheritance so that in future upgrade data should not loss