xxxxxxxxxx
db.students.updateOne(
{ name: "joe" },
{ $push: { scores: { $each: [ 90, 92, 85 ] } } }
)
xxxxxxxxxx
db.students.insertOne( { _id: 1, scores: [ 44, 78, 38, 80 ] } )
db.students.updateOne(
{ _id: 1 },
{ $push: { scores: 89 } }
)
-----------------------
{ _id: 1, scores: [ 44, 78, 38, 80, 89 ] }