[PWA] 12. Intro to IndexedDB

Use the library indexeddb-promised.

Create a database and Stroe:

Import IDB from ' IDB '; // Open (db_name, version, CB) var function (upgradedb) {    var//  CREATE TABLE    //put (value, key)     keyvalstore.put (' World ', ' Hello ') ;

Notice put () function take value frist then key.

Read the key in Stroe:

// read "Hello" in "Keyval"dbpromise.then (function  (db) {    var//  Open a transaction    var//  read the store    return// get value by Key}). Then (function  (val) {    console.log (' The value of "Hello" is: ', Val);});

Write value to store:

//set "foo" to Is "bar" in "Keyval"Dbpromise.then (function(db) {vartx = Db.transaction (' keyval ', ' readwrite ');//Ready for add key value    varKeyvalstore = Tx.objectstore (' keyval ');//Get the storeKeyvalstore.put (' Bar ', ' foo ');//set the value, notice it May is success if any step in transaction fail.    returnTx.complete;//Tx.complete is a promise}). Then (function() {Console.log (' Added Foo:bar to Keyval ');});

[PWA] 12. Intro to IndexedDB