如何将sqldatareader转换为dto列表？

Question

我刚刚开始将所有我的ado.net代码从asp.net页面移动到repo并为每个表创建dto(手动),但现在我不知道将sqldatareader转换为我的列表的有效方法是什么dto对象？

例如,我的dto是Customer.

我正在使用webforms,我没有使用ORM.我想慢慢开始在那里工作.

Answer 1

通常,模式看起来像:

List<Customer> list = new List<Customer>();

using(SqlDataReader rdr = GetReaderFromSomewhere()) {
  while(rdr.Read()) {
     Customer cust = new Customer();
     cust.Id = (int)rdr["Id"];
     list.Add(cust)
  }
}

Answer 2

这是一个简短的示例,说明如何使用数据读取器检索数据:

var customers = new List<Customer>();
string sql = "SELECT * FROM customers";
using (var cnn = new SqlConnection("Data Source=Your_Server_Name;Initial Catalog=Your_Database_Name;Integrated Security=SSPI;")) {
    cnn.Open();
    using (var cmd = new SqlCommand(sql, cnn)) {
        using (SqlDataReader reader = cmd.ExecuteReader()) {
            // Get ordinals (column indexes) from the customers table
            int custIdOrdinal = reader.GetOrdinal("CustomerID");
            int nameOrdinal = reader.GetOrdinal("Name");
            int imageOrdinal = reader.GetOrdinal("Image");
            while (reader.Read()) {
                var customer = new Customer();
                customer.CustomerID = reader.GetInt32(custIdOrdinal);
                customer.Name = reader.IsDBNull(nameOrdinal) ? null : reader.GetString(nameOrdinal);
                if (!reader.IsDBNull(imageOrdinal)) {
                    var bytes = reader.GetSqlBytes(imageOrdinal);
                    customer.Image = bytes.Buffer;
                }
                customers.Add(customer);
            }
        }
    }
}

如果表列可以为空,则reader.IsDBNull在检索数据之前进行检查.