IDB

Back to Hell-licensed code

Download idb.js, Quick start with dummy example, Read the manual, Learn the native API, Dive into W3 Specs

Before you even start

There is a bit misconception among some coders when they first meet IndexedDB. To avoid it, it is important to keep in mind that:

• IndexedDB does not use tables, but object stores. The records do not have to be the same type. They do not have columns.
• IndexedDB works with objects, each record in store can have complex structure. They are not rows.
• IndexedDB does not use SQL, so don't think in SQL here. SQL is for tables. In stores one does not JOIN.
• IndexedDB has indexes and they are necessary for quick basic sorting and filtering. Complex operations need to be done on JS level with help of low level traversing objects called cursors.
• IndexedDB (and thus IDB) has an upgrade phase called by onupgradeneeded event at the beginning of the script, where storage manipulation operations can be performed.

When you start

Brace yourself for complex native API, which is far less intuitive than in webSQL. IDB simplifies it with help of Promises, keeping most but not all IndexedDB features. It is not needed to be familiar with Promises and IndexedDB to start with IDB, but the more features coder knows, the cleaner and simpler code he can write.

Consider running IndexedDB in Web Worker, for it is not dependent on DOM and runs many asynchronous operations, so the main thread is not cluttered with accidental complexity of the data manipulation.

IndexedDB is created locally in origin separated spaces. It can be created even without web server, in the file:// origin.