private void DeleteIncomeTransactionBtn_Click(object sender, EventArgs e)
    {
        var incomeTransactions = DbContext.GetInstance().GetCollection<IncomeTransaction>("income_transactions")
                   .FindAll();

        var code = inputTransactions.SelectedText;
        var ensure = DbContext.GetInstance().GetCollection<IncomeTransaction>("income_transactions").EnsureIndex(r => r.TransactionCode);

        var query = DbContext.GetInstance().GetCollection<IncomeTransaction>("income_transactions").Query()
            .Where(r => r.TransactionCode == code)
            .Select(r => r.Id);

        DbContext.GetInstance().GetCollection<IncomeTransaction>("income_transactions").Delete(query));

    }

我想按下拉列表的选定索引（TransactionCode）删除一条记录。在此代码中，我首先尝试按选定索引查找记录，然后使用此查找此记录的ID。然后删除具有此ID的记录。请帮助我解决此错误。我的错误：无法从“LiteDB.ILiteQueryableResult”转换为“LiteDB.BSON值”。