Je code pour un quiz, mais je suis incertain sur la façon dont je compte le nombre total de questions dans ma base de données. Je sais que j'ai besoin d'une requête de compte, mais je ne sais pas où l'insérer. Voici mon code:Obtenir la table Nombre de lignes C#
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.Sql;
using System.Data.SqlClient;
namespace Quiz_Test
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
String chosenAnswer, correctAnswer;
DataTable table;
int questionNumber;
private void Form1_Load(object sender, EventArgs e)
{
string cnString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Users\\Hannah\\Desktop\\QuizQuestions.accdb";
OleDbConnection conGet = new OleDbConnection(cnString);
OleDbCommand cmdGet = new OleDbCommand();
conGet.Open();
cmdGet.CommandType = CommandType.Text;
cmdGet.Connection = conGet;
cmdGet.CommandText = "SELECT * FROM QuizQuestions ORDER BY rnd()";
OleDbDataReader reader = cmdGet.ExecuteReader();
table = new DataTable();
table.Load(reader);
foreach (DataRow row in table.Rows)
{
labelQuestion.Text = table.Rows[0]["Question"].ToString();
radioButton1.Text = table.Rows[0]["Answer 1"].ToString();
radioButton2.Text = table.Rows[0]["Answer 2"].ToString();
radioButton3.Text = table.Rows[0]["Answer 3"].ToString();
radioButton4.Text = table.Rows[0]["Answer 4"].ToString();
correctAnswer = table.Rows[0]["Correct Answer"].ToString(); ;
questionNumber = 0;
}
conGet.Close();
}
private void btnGoToNextOne_Click(object sender, EventArgs e)
{
String cnString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Users\\Hannah\\Desktop\\QuizQuestions.accdb";
OleDbConnection conGet = new OleDbConnection(cnString);
OleDbCommand cmdGet = new OleDbCommand();
{
conGet.Open();
cmdGet.CommandType = CommandType.Text;
cmdGet.Connection = conGet;
cmdGet.CommandText = "SELECT * FROM QuizQuestions ORDER BY rnd()";
OleDbDataReader reader = cmdGet.ExecuteReader();
reader.Read();
if (radioButton1.Checked)
{
chosenAnswer = reader["Answer 1"].ToString();
}
else if (radioButton2.Checked)
{
chosenAnswer = reader["Answer 2"].ToString();
}
else if (radioButton3.Checked)
{
chosenAnswer = reader["Answer 3"].ToString();
}
else if (radioButton4.Checked)
{
chosenAnswer = reader["Answer 4"].ToString();
}
if (chosenAnswer == reader["Correct Answer"].ToString())
{
labelQuestion.Text = table.Rows[questionNumber]["Question"].ToString();
//and show possible answers:
radioButton1.Text = table.Rows[questionNumber]["Answer 1"].ToString();
radioButton2.Text = table.Rows[questionNumber]["Answer 2"].ToString();
radioButton3.Text = table.Rows[questionNumber]["Answer 3"].ToString();
radioButton4.Text = table.Rows[questionNumber]["Answer 4"].ToString();
correctAnswer = table.Rows[questionNumber]["Correct Answer"].ToString();
questionNumber++;
}
else
{
MessageBox.Show("That is not the correct answer");
}
}
}
}}
Je sais que je dois mettre en "SELECT COUNT (*) à partir QuizQuestions" mais je ne sais pas comment je peux déterminer la 'position' dans l'ensemble des questions afin que je ne comprends pas cette erreur:
IndexOutOfRangeException was unhandled
There is no row at position 5