mongodb check if field exists
db.records.find( { a: { $exists: true } } )mongodb check if field exists
db.records.find( { a: { $exists: true } } )mongodb add or update document fields only if they don't exist
db.foo.update({'field': {$exists : false}}, {$set: {'field': ''}})
// for multiple update do this
db.foo.update({'field': {$exists : false}}, {$set: {'field': ''}}, false, true)Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
