public partial class Form1 : Form
{
OleDbConnection connection = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Conductors.accdb");
OleDbCommand command;
OleDbDataReader dr;
DataTable dt = new DataTable();
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
connection = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=Conductors.accdb");
command = new OleDbCommand();
connection.Open();
command.Connection = connection;
command.CommandText = "SELECT * FROM Condtype";
dr = command.ExecuteReader();
while (dr.Read())
{
comboBox1.Items.Add(dr["Shape"].ToString());
}
connection.Close();
connection = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=Conductors.accdb");
command = new OleDbCommand();
connection.Open();
command.Connection = connection;
command.CommandText = "SELECT * FROM Condtype2";
dr = command.ExecuteReader();
while (dr.Read())
{
comboBox2.Items.Add(dr["Type"].ToString());
}
connection.Close();
}
private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
{
DataTable dt = new DataTable();
string sQry = "SELECT * FROM Conductors where Shape = '" + comboBox1.SelectedItem + "' and Type = '" + comboBox2.SelectedItem + "'";
using (OleDbConnection connection = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=Conductors.accdb"))
{
connection.Open();
using (OleDbCommand command = new OleDbCommand(sQry, connection))
using (OleDbDataReader reader = command.ExecuteReader())
{
dt.Load(reader);
comboBox3.DataSource = dt;
comboBox3.DisplayMember = "Ssize";
comboBox3.ValueMember = "ID";
}
}
}
}
}