We are redeveloping our site and building from scratch on a new server an updated version, new theme etc. However we need to transfer all of the products, categories, customers attributes etc over from the old to the new to get started. We've tried using the built in export/import for the products but the new site says it does not like the file. It looks like we need to import categories etc first. Can this be done directly from the database and copy over the table content from the old to the new? Or is there another way of doing this?
Thanks for your help.
No, I am afraid you have do it manually one by one , when one does updates website content transfer is always considered as big issue.
We upgrade stores for clients we host all the time and there are 5 options we use:
1) sometimes, you can just upgrade the database to a new version and connect it to a fresh store - a bit tricky with extensions and customizations but can work for a simple store
2) export information from old store and import to a new store - not all information can be exported and imported this way
3) if you go from M1 to M2, there is a data migration tool (http://devdocs.magento.com/guides/v2.0/migration/migration-tool-install.html)
4) if above did not work for you, try data migration service from www.shopping-cart-migration.com - you can use them to move data from one version of Magento store to another even if both are M1 or both are M2 stores. Sometimes, this auto data migration does not work but their support is pretty good at fixing things to make sure you get your data (can be expensive but consider time you or your staff will spend to re-enter or re-import data manually and that service often worth the expense)
5) manual table conversion - it's time-consuming and can get expensive but possible and we use it to migrate the information which was not transferred by above tools
Hope this helps.