mongodb get only one field code example

Example 1: mongodb select fields

db.inventory.find( { status: "A" }, { item: 1, status: 1 } )

Example 2: find only one field mongodb

db.students.find({}, {roll:1, _id:0})

Example 3: mongodb project all fields

db.collection.aggregate([
    { "$addFields": { "custom_field": "$obj.obj_field1" } }
])