winforms-sql-connection [ARAGON]

TestWins/Form1.cs

@@ -1,43 +1,94 @@
-using System.Drawing.Text;
 using TestWins.Controller;
+using TestWins.Model;
 
-namespace TestWins;
-
-public partial class Form1 : Form
+namespace TestWins
 {
-    //business
-
-    private readonly StudentController controller = new StudentController();
-    public Form1()
+    public partial class Form1 : Form
     {
-        InitializeComponent();
-        loadData();
-    }
+        private readonly StudentController controller = new StudentController();
+        private DataGridViewRow? selectedRow;
 
-    private void loadData()
-    {
-        dataGridView1.DataSource = controller.getAll();
-    }
+        public Form1()
+        {
+            InitializeComponent();
+            loadData();
+        }
 
-    private void btnAdd_Click(object sender, EventArgs e)
-    {
+        private void loadData()
+        {
+            dataGridView1.DataSource = controller.getAll();
+        }
 
-    }
+        private void btnAdd_Click(object sender, EventArgs e)
+        {
+            if (!ValidateFields()) return;
+            var success = controller.add(GetStudent());
+            ShowResult(success, "Added");
+            ClearAndRefresh();
+        }
 
-    private void btnUpdate_Click(object sender, EventArgs e)
-    {
+        private void btnUpdate_Click(object sender, EventArgs e)
+        {
+            if (selectedRow == null) { MessageBox.Show("Select a row!"); return; }
+            if (!ValidateFields()) return;
+            var success = controller.update(GetStudent());
+            ShowResult(success, "Updated");
+            ClearAndRefresh();
+        }
 
-    }
+        private void btnDelete_Click(object sender, EventArgs e)
+        {
+            if (selectedRow == null) { MessageBox.Show("Select a row!"); return; }
+            if (MessageBox.Show("Delete?", "Confirm", MessageBoxButtons.YesNo) == DialogResult.No) return;
+
+            var success = controller.delete(Convert.ToInt32(selectedRow.Cells["Id"].Value));
+            ShowResult(success, "Deleted");
+            ClearAndRefresh();
+        }
 
-    private void btnDelete_Click(object sender, EventArgs e)
-    {
+        private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
+        {
+            if (e.RowIndex < 0) return;
+            selectedRow = dataGridView1.Rows[e.RowIndex];
+            PopulateFields();
+        }
 
+        // Helpers
+        private bool ValidateFields() => 
+            !string.IsNullOrWhiteSpace(txtName.Text) && !string.IsNullOrWhiteSpace(txtCourse.Text);
 
+        private Student GetStudent() => new()
+        {
+            Id = int.TryParse(txtId.Text, out int id) ? id : 0,
+            Name = txtName.Text,
+            Course = txtCourse.Text,
+            Age = int.TryParse(txtAge.Text, out int age) ? age : 0
+        };
 
-    }
+        private void PopulateFields()
+        {
+            txtId.Text = selectedRow.Cells["Id"].Value?.ToString() ?? "";
+            txtName.Text = selectedRow.Cells["Name"].Value?.ToString() ?? "";
+            txtCourse.Text = selectedRow.Cells["Course"].Value?.ToString() ?? "";
+            txtAge.Text = selectedRow.Cells["Age"].Value?.ToString() ?? "";
+        }
 
-    private void dataGridView1_CellClick(object sender, EventArgs e)
-    {
+        private void ClearAndRefresh()
+        {
+            ClearFields();
+            loadData();
+        }
+
+        private void ClearFields()
+        {
+            txtId.Clear(); txtName.Clear(); txtCourse.Clear(); txtAge.Clear();
+            selectedRow = null;
+        }
 
+        private void ShowResult(bool success, string action)
+        {
+            var msg = success ? $" {action} successfully!" : $" Failed to {action}!";
+            MessageBox.Show(msg, success ? "Success" : "Error");
+        }
     }
 }

TestWins/model/ConnectionSql.cs

@@ -1,22 +1,67 @@
-namespace TestWins.Model;
-
-//dotnet add package MySql.Data
 using MySql.Data.MySqlClient;
+using System;
 
-public class ConnectionSql
+namespace TestWins.Model
 {
-    private readonly string _connectionString = "server=localhost;database=student;uid=root;pwd=root";
-        private MySqlConnection _conn;
-
-    public MySqlConnection connectSql()
+    public class ConnectionSql
     {
+        private readonly string _connectionString = "server=localhost;database=student;uid=root;pwd=root";
+        private MySqlConnection _conn;
 
-        Console.WriteLine("Connecting to DB");
+        public MySqlConnection ConnectSql()
+        {
+            try
+            {
+                Console.WriteLine("Connecting to DB...");
+
+                if (_conn == null || _conn.State == System.Data.ConnectionState.Closed)
+                {
+                    _conn = new MySqlConnection(_connectionString);
+                    _conn.Open(); 
+                }
 
-        _conn = new MySqlConnection(_connectionString);
+                if (_conn.State == System.Data.ConnectionState.Open)
+                {
+                    Console.WriteLine(" Database connection successful");
+                    return _conn;
+                }
+                else
+                {
+                    Console.WriteLine(" Database connection failed");
+                    return null;
+                }
+            }
+            catch (MySqlException ex)
+            {
+                Console.WriteLine($" Database connection error: {ex.Message}");
+                return null;
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($" Unexpected error: {ex.Message}");
+                return null;
+            }
+        }
 
-        Console.WriteLine(_conn == null ? "Datbase Connection Failed" : "Database connection successful");
+        public void CloseConnection()
+        {
+            try
+            {
+                if (_conn != null && _conn.State == System.Data.ConnectionState.Open)
+                {
+                    _conn.Close();
+                    Console.WriteLine("Connection closed");
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"Error closing connection: {ex.Message}");
+            }
+        }
 
-        return _conn;
+        public MySqlConnection GetConnection()
+        {
+            return ConnectSql();
+        }
     }
-}
+}