No, it's not necessary to have
`onerror`/`onsuccess` handlers for every request in IndexedDB. You can use a single set of handlers at the transaction level to handle success or error events for multiple requests within the transaction.
Code Example :
request.onerror = function (event) {
if (request.error.name == 'ConstraintError') {
console.log('Book with such id already exists'); // handle the error
event.preventDefault(); // don't abort the transaction
event.stopPropagation(); // don't bubble error up, "chew" it
} else {
// do nothing
// transaction will be aborted
// we can take care of error in transaction.onabort
}
};?
