This is a golang tool to extract mongodb schema. The main steps are:

1. List all collections from mongdodb database
2. Handle collection one by one
   1. Select 100 documents and analysis document's fields type according object real type. Using []bson.D as result type: var results []bson.D err := c.Find(bson.M{}).Limit(MaxTryRecords).Sort("-_id").All(&results)
   2. For slice []interface{}, also handle at most 100 records.
   3. Handle bson.D as embedded document.

Depends on

1. https://github.com/globalsign/mgo
2. https://gopkg.in/urfave/cli.v1

Sample command: extract_mgo.exe -database mongodb://db_owner:db_owner@localhost:47017/sampledb -format csv -output mongo_schema.csv