C# - SqlDataReader and serialization

Question

Can an SqlDataReader be passed to a session or sent to a client?

For instance, if I retrieved some rows from a database, and want to send this data to another client machine. Can I simply do this by serializing it using json on the server and then deserializing back on the client?

Answer 1

不，只有数据（没有方法或功能）可以被序列化，所以数据阅读器将是无用的，因为你无法调用方法来推进阅读器等。模式是将所有记录读入一个对象列表中阅读器，关闭它，然后将这些对象序列化回客户端。

Answer 2

No, any resource-related object cannot be "passed" to a client.

This wouldn't really make sense. You should "materialize" the data reader and pass the results.

Ie you can create an SqlDataAdapter from your reader, fill a DataTable and pass the DataTable.

Answer 3

No, you have to map the reader to a POCO and that will be serialized. Even if you can technically serialize the SqlDatReader object, it's a VERY BAD Idea. Don't do it. It's trivial to use a micro-orm to map a query to a DTO. Don't complicate your work.

Answer 4

Old Question, but technology provide new solutions.

You can use Protocol Buffers DataReader Extensions for .NET to Serialize SqlDataReader and can be passed to a session or sent to a client

Example:

      string connstring1 = "Data Source=server1;Initial Catalog=northwind;user=xxx;password=xxx";

        //Serializing an IDataReader into a ProtoBuf:

        Stream buffer = new MemoryStream();
        using (var c1 = new SqlConnection(connstring1))
        {
           c1.Open();
            // Serialize SQL results to a buffer
            using (var command = new SqlCommand("SELECT * FROM products", c1))
            using (var reader = command.ExecuteReader())
                DataSerializer.Serialize(buffer, reader);

            // Read them back
            buffer.Seek(0, SeekOrigin.Begin);
            using (var reader = DataSerializer.Deserialize(buffer))
            {
                while (reader.Read())
                {
                    Console.WriteLine(reader["ProductName"]);
                }
            }
        }

    }

you should install nuget package:

   Install-Package protobuf-net-data