Sample to rename multiple fields at the same time in MongoDB: db.yourCollectionName.updateMany( {}, { $rename: { "field1OldName": "field1NewName", "field1OldName": "field2NewName" } } );
The first parameter after the find is the query, in this case {} indicates an empty query (do the following statements on all rows [documents] in the collection. <pre> db.yourCollectionName.find( {}, { 'desiredFieldname': 1 } ).forEach(function(doc) { db.yourCollectionNameupdate( { _id: doc._id}, { $set : { 'desiredFieldname' : doc.desiredFieldname.toLowerCase() } }, { multi: true } […]
MongoDB is not SQL. There can be a schema to enforce types, but often there is no schema. You essentially have to update all the documents in the collection. <pre> db.yourcollectionname.updateMany({}, { $unset: { 'field1': 1, 'field21, 'field31 } }) </pre> I believe the value of “1” is used after each field just because they […]