How do I access IndexedDB data?
How it works.
- First, get the email index object from the Contacts object store.
- Second, use the index to read the data by calling the get() method.
- Third, show the result the console in the onsuccess event handler of the query.
What is cursor in IndexedDB?
The IDBCursor interface of the IndexedDB API represents a cursor for traversing or iterating over multiple records in a database. The cursor has a source that indicates which index or object store it is iterating over.
Is IndexedDB deprecated?
The W3C has announced that the Web SQL database is a deprecated local storage specification so web developer should not use this technology any more. indexeddb is an alternative for web SQL data base and more effective than older technologies.
Is IndexedDB SQL?
IndexedDB does not use Structured Query Language (SQL). It uses queries on an index that produces a cursor, which you use to iterate across the result set.
Where is IndexedDB data stored?
browser profile folder
More specifically, IndexedDB data is stored in the browser profile folder.
What type of DB is IndexedDB?
transactional database system
IndexedDB is a transactional database system, like an SQL-based RDBMS. However, unlike SQL-based RDBMSes, which use fixed-column tables, IndexedDB is a JavaScript-based object-oriented database.
What is the difference between localStorage and IndexedDB?
localStorage is useful for storing smaller amounts of data, it is less useful for storing larger amounts of structured data. So if you want to store significant amounts of structured data then IndexedDB is what you should choose.
How do I update my IndexedDB data?
Mastering IndexedDB (6 Part Series)
- IndexedDB: Step by step 2 Create a database with IndexedBD …
- more parts…
- Add data to IndexedDB 4 Delete data from IndexedDB 5 Get data from IndexedDB 6 Update data from IndexedDB.
Is IndexedDB a NoSQL?
IndexedDB is a large-scale, NoSQL storage system. It lets you store just about anything in the user’s browser. In addition to the usual search, get, and put actions, IndexedDB also supports transactions. You can find an example of an IndexedDB below.
Is IndexedDB asynchronous?
Operations performed using IndexedDB are done asynchronously, so as not to block applications.
Can I store object in IndexedDB?
It lets you store just about anything in the user’s browser. In addition to the usual search, get, and put actions, IndexedDB also supports transactions. Here is the definition of IndexedDB on MDN: “IndexedDB is a low-level API for client-side storage of significant amounts of structured data, including files/blobs.
Why is it better to use IndexedDB instead of localStorage?
How do I open a basic cursor on an index?
We then open a basic cursor on the index using openCursor () — this works the same as opening a cursor directly on an ObjectStore using IDBObjectStore.openCursor except that the returned records are sorted based on the index, not the primary key. Finally, we iterate through each record, and insert the data into an HTML table.
How does the open () function work in IndexedDB?
The call to the open () function returns an IDBOpenDBRequest object with a result (success) or error value that you handle as an event. Most other asynchronous functions in IndexedDB do the same thing – return an IDBRequest object with the result or error. The result for the open function is an instance of an IDBDatabase.
Where can I find the documentation on the IndexedDB API?
For the reference documentation on the IndexedDB API, see the IndexedDB API article and its subpages. This article documents the types of objects used by IndexedDB, as well as the methods of the asynchronous API (the synchronous API was removed from spec).
What is the difference between normal and key cursors on indexes?
You can open two different types of cursors on indexes. A normal cursor maps the index property to the object in the object store. A key cursor maps the index property to the key used to store the object in the object store. The differences are illustrated here: