Storing a Blob will use a lot less space and resources as there is no longer a need for conversion to base64. You can even store “text/plain” objects as blobs: var blob = new Blob([‘blob object’], {type: ‘text/plain’}); var store = db.transaction([‘entries’], ‘readwrite’).objectStore(‘entries’); // Store the object var req = store.put(blob, ‘blob’); req.onerror = function(e) … Read more
You can’t create an objectStore in an onsuccess method. You can only do this in a upgradeneeded event. Quote from docs: When you create a new database or increase the version number of an existing database (by specifying a higher version number than you did previously, when Opening a database), the onupgradeneeded event will be … Read more
First of all, the one that has been deprecated by W3C is WebSQL not SQLite IndexedDB – It is incompatible with many types of mobile OS and is only compatible with certain types of versions of mobile OS Developers cannot use SQL with IndexedDB. They can with SQLite and WebSQL Most developers actively avoid using … Read more
In the onupgradeneeded callback you can check the version. (e.target.result.oldversion). If it is 0, the db didn’t exist. Edit: After some investigation. You can’t be 100% sure if a new db is created. One thing I am sure of is the fact that you can only work with an indexeddb if it has a version … Read more
The difference between add and put is same as in any API. If you try to insert an element with key that already exist using the put function it will trigger and update of the existing element, however if you use the add function and element with same id exist you will get an error … Read more
It’s like localStorage, so it’s cross-session, meaning restarting browser or system won’t affect what is stored in it. However, user can clear it like clearing cookie. So it’s just like persistent cookie, you don’t trust it from the server-side, and you always need to check its integrity.
Check out this answer to the same question. It is more detailed than the answer I give here. The keypath parameter to store.createIndex and IDBKeyRange methods can be an array. So, crude example: // In onupgradeneeded var store = db.createObjectStore(‘mystore’); store.createIndex(‘myindex’, [‘prop1′,’prop2’], {unique:false}); // In your query section var transaction = db.transaction(‘mystore’,’readonly’); var store = … Read more
I’m new to IndexedDB myself but I too have been thinking a lot about how I would use IndexedDB for purposes like this. The first thing I would suggest, if you haven’t done it already, is to look at how other key-value / document databases (CouchDB, MongoDB, etc.) work, since that’s essentially the type of … Read more
Web SQL is deprecated per https://www.w3.org/TR/webdatabase/. You can use IndexedDB if you need to store structured client specific data that you do not store in the server side or you do not want to request from the server every time. Also as opposed to localStorage, IndexedDB is async so it is more performant. It supports … Read more
Update May 2020: Chrome now lets an origin use 60% of the storage device’s space (Real nitty gritty: “storage device” is the partition containing the chrome profile directory). Updated article here https://web.dev/storage-for-the-web/#how-much The rule of thumb is 6% (edit 2015-Jul: was 10%) of the available space on the user’s hard drive, less if your origin … Read more