# Version

An instance of a Version class can only be returned from the Dexie.version() method. Use it to define the schema and any upgrader function for that specific version.

#### Sample

```javascript
var db = new Dexie("FriendsAndPetsDatabase");
db.version(2).stores({
  friends: "++id,name,birthdate,sex",
  pets: "++id,name,kind"
}).upgrade (trans => {
  var YEAR = 365 * 24 * 60 * 60 * 1000;
  return trans.friends.toCollection().modify (friend => {
    friend.birthdate = new Date(Date.now() - (friend.age * YEAR));
    delete friend.age;
  });
});
// Always keep the declarations previous versions as long as there might be users having them running.
db.version(1).stores({
  friends: "++id,name,age,sex",
  pets: "++id,name,kind"
});
db.open(); 
```

### Methods

#### [stores()](/version/version.stores.md)

Specify the database schema (object stores and indexes) for a certain version.

#### [upgrade()](/version/version.upgrade.md)

Specify an upgrade function for upgrading between previous version to this one.

### See Also

Database Versioning


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