将多个复选框列表值插入sql db asp.net C＃

Question

I am trying to insert multiple CheckBoxList values that are INT to a SQL DB using ASP.NET C#. I have set a breakpoint in my code and the loop works but once it picks up the first selected value, it stays with that value and causes a Primary Key Constraint. In the end, it just inserts one value. After a couple days of research, all my findings show how to insert multiple strings to a SQL DB but none for INT. Any help is much appreciated.

    for (int i = 0; i < cbAvailableEntities.Items.Count - 1; i++)
{
    SqlConnection con = new SqlConnection(connString);
        SqlCommand cmd = new SqlCommand("InsertProjectEntity", con);

        using(con)
        {
            con.Open();
            using(cmd)
            {
                 if (cbAvailableEntities.Items[i].Selected)
                 {
                     //This code gets the Project ID that is to be associated with the new info
                     DALSectionAccessData LastProjectID = new DALSectionAccessData(connString);
                     //This puts the Project ID needed into the variable _pID
                     int _pID = LastProjectID.GetLastLogReportID();
                     cmd.CommandType = CommandType.StoredProcedure;
                     nr.Entities = cbAvailableEntities.SelectedValue;
                     cmd.Parameters.AddWithValue("@ProjectID", _pID);
                     cmd.Parameters.AddWithValue("@CorpID", nr.Entities);
                     cmd.ExecuteNonQuery();
                  }
            }
        }
}

This is what the error says

Server Error in '/' Application.

Violation of PRIMARY KEY constraint 'PK_ProjectEntity'. Cannot insert duplicate key in object 'dbo.ProjectEntity'. The statement has been terminated.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Violation of PRIMARY KEY constraint 'PK_ProjectEntity'. Cannot insert duplicate key in object 'dbo.ProjectEntity'. The statement has been terminated.

Answer 1

Inside your loop, you are checking in the if() statement to see if Item[i] is selected, but if it is you are not doing anything with Item[i] to differentiate one iteration from the next. Therefore you are running the same exact code for every selected item in the checkboxlist, rather than doing something different for each.

Try changing this:

cmd.Parameters.AddWithValue("@CorpID", nr.Entities);

to something like this:

cmd.Parameters.AddWithValue("@CorpID", cbAvailableEntities.Items[i].Value);