I need to add a new column name id INTEGER AUTOINCREMENT
and a new table for the current database for my existing table. How to use 'onUpgrade'? Is it need to change the version number?
initDb() async {
io.Directory documentsDirectory = await getApplicationDocumentsDirectory();
String path = join(documentsDirectory.path, "HelperDatabase.db");
var theDb = await openDatabase(path, version: 1, onCreate: _onCreate, onUpgrade: _onUpgrade);
return theDb;
}
How to use _onUpgrade
void _onUpgrade(Database db, int oldVersion, int newVersion)async{
}
Is it need to add column also?
void _onCreate(Database db, int version) async {
await db.execute(
"""CREATE TABLE AssetAssemblyTable(e INTEGER, a INTEGER, c INTEGER)""");
To update your DB from old version, you should change version
to 2
.
You should change onCreate
and onUpdate
like below.
// This is called for new users who have no old db
void _onCreate(Database db, int version) async {
// if `AssetAssemblyTable` has a new column in version 2, add the column here.
await db.execute(
"""CREATE TABLE AssetAssemblyTable(e INTEGER, a INTEGER, c INTEGER)""");
)
await db.execute("CREATE TABLE NewTable...") // create new Table
}
// This is called for existing users who have old db(version 1)
void _onUpgrade(Database db, int oldVersion, int newVersion)async{
// In this case, oldVersion is 1, newVersion is 2
if (oldVersion == 1) {
await db.execute("ALTER TABLE AssetAssemblyTable...") // add new column to existing table.
await db.execute("CREATE TABLE NewTable...") // create new Table
}
}
more example is below
https://github.com/tekartik/sqflite/blob/master/sqflite/doc/migration_example.md