I was in this exact situation two weeks ago. Because Mongo databases tend to have an implicit schema, I used variety.js (https://github.com/variety/variety http

I was in this exact situation two weeks ago. Because Mongo databases tend to have an implicit schema, I used variety.js (https://github.com/variety/variety https://github.com/variety/variety) to first uncover it for a given collection. I then hand-created a SQL table that corresponds to said collection, using variety.js's output as a guide for what types to use.