[{_id:"1232",title:"Product 1",order:1,code:"A",status:"active"},{_id:"4444",title:"Product 2",order:2,code:"B",status:"active"},{_id:"2232",title:"Product 3",order:3,code:"A",status:"unActive"},{_id:"55555",title:"Product 4",order:4,code:"C",status:"active"},{_id:"66666",title:"Product 5",order:5,code:"D",status:"active"},{_id:"2222",title:"Product 6",order:6,code:"C",status:"active"}]

db.collection.update({status:"active"},[{$set:{code:{$switch:{branches:[{case:{$eq:["$code","A"]},then:"A1"},{case:{$eq:["$code","B"]},then:"B1"},{case:{$eq:["$code","C"]},then:"C1"},{case:{$eq:["$code","D"]},then:"D1"}],default:""/**can remove if switch satisfy at least 1 condition above*/}}}}],{multi:true})