您应该将所有更改都放在可以使用以下代码的onUpgrade方法中:

You should put all changes in your onUpgrade method you can use this code:

@Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    String sql = "ALTER TABLE " + TABLE_SECRET + " ADD COLUMN " +
     "name_of_column_to_be_added" + " INTEGER";
    db.execSQL(sql);        
}        

这将在当前数据库中添加一列.您的数据库不会丢失数据.提醒:当执行getWriteableDatabase或getReadableDatabase并且数据库版本与旧版本不同时，将调用onUpgrade.

this adds a column in your current database. Your database will not lose data. Reminder: onUpgrade will be called when getWriteableDatabase or getReadableDatabase is executed AND the version of your database is different from your older version.