Hi,

Merging two Odoo databases, even when running the same version, is a complex task, and there is no official one-click solution. However, various proven strategies can help you combine data intelligently depending on your needs.

1. Export / Import Selected Data (Simplest):

           - Selectively merging Customers, Products, Sales Orders without disturbing existing data.

   Use built-in CSV/XML export/import:

    Export key models (e.g., res.partner, product.template, product.product, sale.order, account.move).

    Before import, clean and remap IDs, ensuring any references (like partner_id) are updated.

2- Multi-Company Consolidation (Alternative)

           - If the ultimate goal is combining companies rather than merging historical data:                                         - Configure one database as a multi-company instance.

                           - Migrate one DB’s data first.

                           - Then import the other DB’s customers, products, and transactions into the same company structure.

                           - Still requires export/import or scripting, but uses Odoo’s native multi-company architecture.

NOTE:-

           - Back up both databases completely using pg_dump or Odoo tools.

           - Set up a test environment and run the entire merge flow there first.

           - Never operate directly on live databases without tested backups.

Hope it helps