如何获取 SQL 服务器表来存储列表？

Question

As a java developer, this is possible easily. But I wasn't able to achieve it in C#. I want to get data from the SQL Server database and store them in a list that is of type object to meet the table needs.

The object:

class Category
{
    public int Id { get; set; }
    public string Name { get; set; }
}

and the table in the database:

and the code:

public List<Category> GetCategoryList() 
{
        connect.Open();

        SqlCommand cmd = new SqlCommand("Select * From Category", connect);

        int i = cmd.ExecuteNonQuery();

        connect.Close();
}

I believe there is something named DataReader I got to use it but I couldn't find an explanation or an example of how to use it in such a situation like mine

Answer 1

public List<Category> GetCategoryList() 
{
    List<Category> columnData = new List<Category>();
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        connection.Open();
        SqlCommand cmd = new SqlCommand("Select * From Category", connect);
        using (SqlDataReader reader = cmd.ExecuteReader())
        {
            while (reader.Read())
            {
                columnData.Add(new Category {
                    Id= reader["Id"] is DBNull ? null : int.Parse(reader["Id"]),
                    Name = reader["Name"] is DBNull ? null : reader["Name"].ToString() 
                });
            }         
        }
    }
    return columnData;
}