将组合框项目添加到数据库中

Question

有点麻烦。我试图添加组合框项目到我的数据库，但它不起作用。

代码：

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; 
    } 

我想在我的数据库中创建每个组合框项目的新行，但所有的组合框项出现在单细胞，这将给我：

System.Windows.Forms.ComboBox+ObjectCollection 

是否可以将组合框项添加到我的数据库中，并且每个组合框项在数据库中创建一个新行？谢谢！对不起，有任何困惑。

Answer 1

您不应该在一个命令中添加整个项目。相反，您应该使用foreach循环并逐个添加oitems。

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; 
     } 
    } 
}