Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{_id:"1",val:"admin"},{_id:"2",val:"employee"},{_id:"3",val:"admin"}]
Query
db.collection.update({},[{"$set":{"val":{"$concat":["$val","-en"]}}}],{"multi":true})
Result