I'm currently building a program which stores messages between users in a database and returns these messages to the user when the button below gets pressed. I'm using a SQL CE database using a OleDbConnection and using a DataReader.
private void button3_Click(object sender, EventArgs e)
{
string [] lec_name = new string [10] ;
string [] content = new string [10] ;
string conn = "Provider=Microsoft.SQLSERVER.CE.OLEDB.3.5;Data Source=C:\\Users\\Leon\\Admin.sdf";
OleDbConnection connection = new OleDbConnection(conn);
OleDbCommand command = connection.CreateCommand();
command.CommandText = "SELECT * FROM Contact_DB WHERE Student_ID =" + iD + " AND Direction = '" + "To the student" + "'";
try
{
connection.Open();
}
catch (Exception ex)
{
MessageBox.Show("" + ex.Message);
}
OleDbDataReader reader = command.ExecuteReader();
int up = 0;
int count = 0;
while (reader.Read())
{
lec_name[up] = reader["Lecturer_Name"].ToString();
content[up] = reader["Description"].ToString();
up++;
MessageBox.Show("The lecturer " + lec_name[count] + " has messaged you saying :" + "\n" + content[count]);
count++;
}
}
This code works for my Student class but when I reuse the code with minor changes within the Lecturer class the OledbDataReader says null, anyone know why?
Btw the values being returned aren't null the reader itself is null.
Below is the non working code.
private void button2_Click(object sender, EventArgs e)
{
string [] studentID = new string [10] ;
string [] content = new string [10] ;
string conn = "Provider=Microsoft.SQLSERVER.CE.OLEDB.3.5;Data Source=C:\\Users\\Leon\\Admin.sdf";
OleDbConnection connection = new OleDbConnection(conn);
OleDbCommand command = connection.CreateCommand();
command.CommandText = "SELECT * FROM Contact_DB WHERE Lecturer_Name =" + full + " AND Direction = '" + "To the lecturer" + "'";
try
{
connection.Open();
}
catch (Exception ex)
{
MessageBox.Show("" + ex.Message);
}
OleDbDataReader reader1 = command.ExecuteReader();
int up = 0;
int count = 0;
while (reader1.Read())
{
studentID[up] = reader1["Student_ID"].ToString();
content[up] = reader1["Description"].ToString();
up++;
}
MessageBox.Show("The student " + studentID[count] + " has messaged you saying :" + "\n" +content[count]);
}
}
