DJBonez
C# MySQL Windows form application
To preface this question I am learning development in C# on my own, no classes or formal training.
I am writing a very simple app to get familiarized with windows forms and databases. I have a working app, however; if I want to add a new field in the database, then go to the class where I list all my fields with public string or int. Then go to the DAO I created, where have it reading the table. I always get NULL issue, if I back out the new field in all the locations everything works again.
Sample of the class
namespace csapp
public class Customers
{
public int CustomerID { get; set; }
public string? BusinessName { get; set; }
public string? LastName { get; set; }
public string? FirstName { get; set; }....
addition when it breaks
public string? OtherPhone {get;set;}
Sample of the DAO file
internal class csappDAO
{
string connectionString = "datasource=localhost;port=3306;username=admin;password=admin;database=csappdb;";
public List<Customers> getAllCustomers() { // start with an empty list List<Customers> returnThese = new List<Customers>(); // connect to the mysql server MySqlConnection connection = new MySqlConnection(connectionString); connection.Open(); // define the sql statement to fetch all customers MySqlCommand command = new MySqlCommand("SELECT * FROM customers", connection); using (MySqlDataReader reader = command.ExecuteReader()) { while (reader.Read()) { Customers a = new Customers { CustomerID = reader.GetInt32(0), BusinessName = reader.GetString(1), LastName = reader.GetString(2), FirstName = reader.GetString(3),... addition when it breaks OtherPhone=reader.GetString(21) Hopefully this makes since
public List<Customers> getAllCustomers() { // start with an empty list List<Customers> returnThese = new List<Customers>(); // connect to the mysql server MySqlConnection connection = new MySqlConnection(connectionString); connection.Open(); // define the sql statement to fetch all customers MySqlCommand command = new MySqlCommand("SELECT * FROM customers", connection); using (MySqlDataReader reader = command.ExecuteReader()) { while (reader.Read()) { Customers a = new Customers { CustomerID = reader.GetInt32(0), BusinessName = reader.GetString(1), LastName = reader.GetString(2), FirstName = reader.GetString(3),... addition when it breaks OtherPhone=reader.GetString(21) Hopefully this makes since
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