Convert C# Object to and from Varbinary using Linq to SQL

Question

I want to be able to save any C# object in a single column of a SQL database table. I am not clear how to convert the object into a varbinary or get it back from a varbinary. My SystemContextObjects table has an OptionValue column that is Varbinary(max).

var dc1 = new DataContextDataContext();
var optionUpdate = dc1.SystemContextObjects.SingleOrDefault(o => o.OptionId == OptionId && o.OptionKey == OptionKey);
if (optionUpdate != null)
{
    optionUpdate.OptionValue = Value;  <===== NEED HELP HERE...
    optionUpdate.DateCreated = DateTime.Now;
    optionUpdate.PageName = PageName;
    var ChangeSet = dc1.GetChangeSet();
    if (ChangeSet.Updates.Count > 0)
    {
        dc1.SubmitChanges();
        return;
    }
}

Answer 1

I wound up using JSON to accomplish this. I serialize/deserialize the class to/from a string and store that. Works fine.

Answer 2

You can use a binary serializer for this, e.g. using the BinaryFormatter - but your classes must be serializable and be marked as such, here a simple example:

You have a simple Person class and mark it as serializable:

[Serializable]
public class Person
{
    public string Name { get; set; }
    public string Address { get; set; }
}

You can then serialize it using a memory stream to extract a byte array representing the object:

Person p = new Person() { Name = "Fred Fish", Address = "2 Some Place" };
using (MemoryStream ms = new MemoryStream())
{
    BinaryFormatter formatter = new BinaryFormatter();
    formatter.Serialize(ms, p);

    ms.Position = 0;
    byte[] personData = ms.ToArray(); // here's your data!
}

To re-create a Person object from a byte array you use de-serialization which works similar:

byte[] personData = ...
using (MemoryStream ms = new MemoryStream(personData))
{
    BinaryFormatter formatter = new BinaryFormatter();
    Person p = (Person)formatter.Deserialize(ms);
}