const addingAttribute=async (req,res)=>{
let data = req.body
let findPublisher=await publisherModel.find({$or:[{name:'Penguin'},{name:' HarperCollin'}]}).select({_id:1})
console.log(findPublisher)
let updateBook=await bookModel1.updateMany({publisher:arr},{$set:data},
{new:true})
console.log(updateBook)
res.send({msg:updateBook})
}
For the books published by 'Penguin' and 'HarperCollins', update this key to true.
but this code is updating for only the first value this is bcoz I am a using or can u please tell me anything else
MongoDB's find returns something called a database cursor. You have to exercise the cursor's API to chase through all the values it is presenting.