bulkAdd-multiTrans.js

connection.onsuccess = (e) => {
    var db = e.target.result;
    let startedTime = Date.now();
    console.log(`Started on - ${startedTime}`);
    const trans = db.transaction('contacts', 'readwrite');
    const store = trans.objectStore('contacts');
    store.clear();
    let addedContacts = 0;
    for (let i = 0; i < totalLength; i++ ) {
        const transaction = db.transaction('contacts', 'readwrite');
        const storeInside = transaction.objectStore('contacts');
        var req = storeInside.add(contacts[i], contact.id);
        req.onsuccess = (evt) => {
            addedContacts++;
            console.log(`Contact - ${i + 1} added.`);
            if (i+1 === totalLength) {
                if (addedContacts === totalLength) {
                    console.log(`--------------------------------------------------------------------`);
                    console.log(`All contacts successfully added in DB.`);
                    const endedTime = Date.now();
                    console.log(`Ended on - ${endedTime}`);
                    console.log(`Total time taken - ${endedTime - startedTime} ms`);
                } else {
                    console.log(`--------------------------------------------------------------------`);
                    console.log(`Could not add every conatcts to the db. Some may be missing.`)
                }
            }            
        };
        req.onerror = (evt) => {
            console.log(`XXXX Something went wrong while adding contact - ${i + 1}.`);
            console.log(evt);
        };
    }
};