在ASP.NET中訪問MySQL數據庫時，遵循最佳實踐可以幫助提高代碼質量、性能和安全性。以下是一些建議的最佳實踐：

1. 使用ORM工具

使用對象關系映射（ORM）工具如Entity Framework Core可以簡化數據庫操作，提高開發效率。

// 安裝Entity Framework Core和MySql.Data.EntityFrameworkCore包
public class ApplicationDbContext : DbContext
{
    public DbSet<ApplicationUser> ApplicationUsers { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseMySQL("server=localhost;port=3306;database=mydb;uid=root;password=mypassword");
    }
}

2. 使用參數化查詢

防止SQL注入攻擊，使用參數化查詢。

using MySql.Data.MySqlClient;

string connectionString = "server=localhost;port=3306;database=mydb;uid=root;password=mypassword";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
    connection.Open();
    string query = "SELECT * FROM users WHERE username = @username";
    using (MySqlCommand command = new MySqlCommand(query, connection))
    {
        command.Parameters.AddWithValue("@username", "john_doe");
        using (MySqlDataReader reader = command.ExecuteReader())
        {
            while (reader.Read())
            {
                // Process the result
            }
        }
    }
}

3. 使用連接池

確保數據庫連接被有效地重用，使用連接池可以提高性能。

string connectionString = "server=localhost;port=3306;database=mydb;uid=root;password=mypassword";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
    connection.Open();
    // Perform database operations
}

4. 異常處理

在數據庫操作中添加適當的異常處理，確保應用程序的穩定性。

try
{
    using (MySqlConnection connection = new MySqlConnection(connectionString))
    {
        connection.Open();
        string query = "SELECT * FROM users WHERE username = @username";
        using (MySqlCommand command = new MySqlCommand(query, connection))
        {
            command.Parameters.AddWithValue("@username", "john_doe");
            using (MySqlDataReader reader = command.ExecuteReader())
            {
                while (reader.Read())
                {
                    // Process the result
                }
            }
        }
    }
}
catch (MySqlException ex)
{
    // Handle the exception
    Console.WriteLine("Error: " + ex.Message);
}

5. 事務管理

在需要保證數據一致性的操作中使用事務。

using (MySqlConnection connection = new MySqlConnection(connectionString))
{
    connection.Open();
    using (MySqlTransaction transaction = connection.BeginTransaction())
    {
        try
        {
            string query1 = "INSERT INTO users (username, email) VALUES (@username, @email)";
            using (MySqlCommand command1 = new MySqlCommand(query1, connection, transaction))
            {
                command1.Parameters.AddWithValue("@username", "john_doe");
                command1.Parameters.AddWithValue("@email", "john@example.com");
                command1.ExecuteNonQuery();
            }

            string query2 = "UPDATE orders SET status = 'shipped' WHERE order_id = @order_id";
            using (MySqlCommand command2 = new MySqlCommand(query2, connection, transaction))
            {
                command2.Parameters.AddWithValue("@order_id", 123);
                command2.ExecuteNonQuery();
            }

            transaction.Commit();
        }
        catch (MySqlException ex)
        {
            transaction.Rollback();
            // Handle the exception
            Console.WriteLine("Error: " + ex.Message);
        }
    }
}

6. 配置管理

將數據庫連接字符串和其他配置信息存儲在安全的地方，如appsettings.json。

{
  "ConnectionStrings": {
    "MySqlConnection": "server=localhost;port=3306;database=mydb;uid=root;password=mypassword"
  }
}

在代碼中讀取配置：

public class ApplicationDbContext : DbContext
{
    public DbSet<ApplicationUser> ApplicationUsers { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseMySQL(Configuration.GetConnectionString("MySqlConnection"));
    }
}

通過遵循這些最佳實踐，你可以確保在ASP.NET中訪問MySQL數據庫時代碼的健壯性、安全性和性能。