widness
1/14/2018 - 4:15 PM

Database versioning IndexDB

Assuming the database we created in the previous example still exists in the browser, when this executes upgradeDb.oldVersion is 2. case 0 and case 1 are skipped and the browser executes the code in case 2, which creates a "description" index. Once all this has finished, the browser has a database at version 3 containing a "store" object store with "price" and "description" indexes.

versioning IndexDB
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var dbPromise = idb.open('test-db7', 3, function(upgradeDb) {
  switch (upgradeDb.oldVersion) {
    case 0:
      upgradeDb.createObjectStore('store', {keyPath: 'name'});
    case 1:
      var storeOS = upgradeDb.transaction.objectStore('store');
      storeOS.createIndex('price', 'price');
    case 2:
      var storeOS = upgradeDb.transaction.objectStore('store');
      storeOS.createIndex('description', 'description');
  }
});