你能幫我嗎? 我想在應用程序中升級我的數據庫。 我需要按名稱「警報」創建新列。 我怎麼能在onUpgrade()方法中做到這一點? 在谷歌我沒有找到需要的信息。 以及如何與舊數據庫中的信息保存到新的數據庫我如何在Android上升級我的數據庫
我的代碼:
public static final String DB_NAME = "database.db";
public static final int DB_VESION = 1;
public static final String ID_COLUMN = "_id";
public static final String NOTE_COLUMN = "note";
public static final String DATE_COLUMN = "date_create";
public static final String STATE_COLUMN = "state";
public static final String DAY_STATE_COLUMN = "day_state";
public static final String ALARM_COLUMN = "alarm";
public final String[] allColumns = {ID_COLUMN, DATE_COLUMN, NOTE_COLUMN, STATE_COLUMN, DAY_STATE_COLUMN};
public static final String TABLE_NAME = "notes";
@Override
public void onCreate(SQLiteDatabase db) {
final String CREATE_DB = "CREATE TABLE " + TABLE_NAME + " (" +
ID_COLUMN + " INTEGER PRIMARY KEY AUTOINCREMENT," +
DATE_COLUMN + " LONG NOT NULL," +
NOTE_COLUMN + " VARCHAR(140) NOT NULL," +
STATE_COLUMN + " INTEGER NOT NULL," +
DAY_STATE_COLUMN + " LONG" +
");";
db.execSQL(CREATE_DB);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
//how i can do this????
onCreate(db);
}
在此先感謝