I’m aware this is a pretty common issue. I recently tried to move from Strapi Mongo to PS SQL so i can eventually upgrade to 4.
I made the dockers and followed the tutorial according to the strapi migration script at migration-scripts/v3-mongodb-v3-sql at main · strapi/migration-scripts · GitHub
I did run it several time, making correction for missing tables and column along the way. I checked the status of my collections along the way as well and everything seemed fine. when I completed everything i bump into two problems
- For some collections the fetch fails with “An error occurred during models config fetch” with the follwoing logs
error TypeError: Cannot read property 'split' of undefined
at eventNames (...node_modules/bookshelf/lib/base/events.js:10:35)
at Child.trigger (.../node_modules/bookshelf/lib/base/events.js:74:5)
at EagerRelation.<anonymous> (....node_modules/bookshelf/lib/base/eager.js:53:44)``
-if I tried to add new data from the data I have been getting Invalid input Data please verify unique constraints
error Error: Duplicate entry
at handleDatabaseError (…node_modules/strapi-connector-bookshelf/lib/utils/errors.js:25:11)
at Object.create (…node_modules/strapi-connector-bookshelf/lib/queries.js:60:14)
`
Any help would be great, I can provide dump and cms as well 
migration logs:
2024-06-03T19:45:15.459Z error: Null componentId for mongoLink.ref: 62724b6fa9f6400020fbf6b3, key: headerBox
2024-06-03T19:45:15.461Z error: Null componentId for mongoLink.ref: 65412ef585131f001fcc232a, key: headerBox
2024-06-03T19:45:15.474Z verbose: Processing collection components_third_party_widgets_viume_surveys
2024-06-03T19:45:15.476Z info: Cleaning Up...
2024-06-03T19:45:15.480Z info: Migration Complete
`
<i>This topic has been created from a Discord post (1247469862322966578) to give it more visibility.
It will be on Read-Only mode here.
<a href="https://discord.com/channels/811989166782021633/1247469862322966578/1247469862322966578">Join the conversation on Discord</a></i>