将组合框项目添加到数据库

Question

Having a little trouble. I'm trying to add combobox items to my database but It doesn't work.

code:

string con = "Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=Database;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False";
string connectionString = con;
using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand cmd = new SqlCommand("INSERT INTO JobRoles (Jobroles) VALUES (@jr)");
    cmd.CommandType = CommandType.Text;
    cmd.Connection = connection;
    cmd.Parameters.AddWithValue("@jr", comboBox1.Items.ToString());

    connection.Open();
    try
    {
        cmd.ExecuteNonQuery();
    }
    catch (Exception)
    {
        MessageBox.Show("Datebase error. Please contact software engineer.", "Error 303");
        return;
    }

I'm trying to create a new row per combo box item in my database but all the combo box items appear in a single cell which will give me this:

System.Windows.Forms.ComboBox+ObjectCollection

is it possible to add combo box items into my database and with each combo box item creates a new row in the database? Thanks! Sorry for any confusion.

Answer 1

You shouldn't add the whole items in one command. Instead you should use a foreach loop and add the oitems one by one.

string con = "Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=Database;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False";
string connectionString = con;

foreach (var item in comboBox1.Items) //loop to go through the items one by one
{
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        SqlCommand cmd = new SqlCommand("INSERT INTO JobRoles (Jobroles) VALUES (@jr)");
        cmd.CommandType = CommandType.Text;
        cmd.Connection = connection;
        cmd.Parameters.AddWithValue("@jr", item.ToString()); //Add each item to database separately 

        connection.Open();
        try
        {
            cmd.ExecuteNonQuery();
        }
        catch (Exception)
        {
            MessageBox.Show("Datebase error. Please contact software engineer.", "Error 303");
            return;
        }
    }
}