The oldVersion
read-only property of the IDBVersionChangeEvent
interface returns the old version number of the database.
When the opened database doesn't exist yet, the value of oldVersion
is 0.
var dbName = "sampleDB";
var dbVersion = 2;
var request = indexedDB.open(dbName, dbVersion);
request.onupgradeneeded = function(e) {
var db = request.result;
if (e.oldVersion < 1) {
db.createObjectStore("store1");
}
if (e.oldVersion < 2) {
db.deleteObjectStore("store1");
db.createObjectStore("store2");
}
};