问指定的C# SQLite和SQL命令转换无效

EN

    public void GetQuestion(int categoryRef)
    {
        Console.Clear();

        int arrayIndex = 0;

        int qListIndex = 0;

        int idListIndex = 0;

        List<string> qList = new List<string>();

        List<int> idList = new List<int>();

        int ansNr = 1;

        bool[] isTrue = new bool[3];


        SQLiteDataReader sqReader;

        SQLiteCommand sqCommand = new SQLiteCommand(sqConnection);

        try
        {
            sqCommand.CommandText = "SELECT Question, ID FROM Questions WHERE CategoryRef=" + categoryRef.ToString();
            sqCommand.Connection.Open();
            sqReader = sqCommand.ExecuteReader();
            foreach (var item in sqReader)
            {
                qList.Add(sqReader.GetString(0));
                idList.Add(sqReader.GetInt32(1));
            }
            sqReader.Close();
        }
        finally
        {
            sqConnection.Close();    
        }

        for (int i = 0; i < qList.Count; i++)
        {   
            try
            {
                sqCommand.CommandText = "SELECT Answer FROM Answers WHERE QuestionRef=" + idList[idListIndex].ToString();
                sqConnection.Open();
                sqReader = sqCommand.ExecuteReader();
                Console.WriteLine(qList[qListIndex]);
                foreach (var answer in sqReader)
                {
                    Console.WriteLine(ansNr + ":" + sqReader.GetString(0));

                    ansNr++;
                }
                sqReader.Close();
            }
            finally
            {
                sqConnection.Close();
            }

            try
            {   
                //THIS CODE FAILS 2'nd TIME IT LOOPS THROUGH
                sqCommand.CommandText = "SELECT IsTrue FROM Answers WHERE QuestionRef=" + idList[idListIndex].ToString();
                sqConnection.Open();
                sqReader = sqCommand.ExecuteReader();
                foreach (var item in sqReader)
                {

                    isTrue[arrayIndex] = sqReader.GetBoolean(0); //<-- Specified cast is not valid.
                    arrayIndex++;


                }
                sqReader.Close();
            }
            finally
            {

                sqConnection.Close();
            }

            string input = Console.ReadLine();
            int number = Convert.ToInt32(input);

            switch (number)
            {
                case 1:
                    if (isTrue[0] == true)
                    {
                        Console.WriteLine("Correct");
                    }
                    if (isTrue[0] == false)
                    {
                        Console.WriteLine("False");
                    }
                    break;

                case 2:
                    if (isTrue[1] == true)
                    {
                        Console.WriteLine("Correct");
                    }
                    if (isTrue[1] == false)
                    {
                        Console.WriteLine("False");
                    }
                    break;

                case 3:
                    if (isTrue[2] == true)
                    {
                        Console.WriteLine("Correct");
                    }
                    if (isTrue[2] == false)
                    {
                        Console.WriteLine("False");
                    }
                    break;
            }
            Console.ReadLine();
            idListIndex++;
            qListIndex++;
            arrayIndex = 0;
            ansNr = 1;
        }
    }