Serialize Expando

ExpandoJsonWriter.cs

public class ExpandoJsonWriter : IJsonWriter
{
    private readonly IOutputWriter _outputWriter;
    private readonly JavaScriptSerializer _jsonSerializer;

    public ExpandoJsonWriter(IOutputWriter outputWriter)
    {
        _outputWriter = outputWriter;
        _jsonSerializer = new JavaScriptSerializer();
    }

    public void Write(object output)
    {
        Write(output, MimeType.Json.ToString());
    }

    public void Write(object output, string mimeType)
    {
        string json;
        if (output is ExpandoObject || output is List<ExpandoObject>)
        {
            if (output is ExpandoObject) json = SerializeExpando(output);
            else json = "[" + ((List<ExpandoObject>) output)
                .Select(SerializeExpando)
                .Aggregate((a, i) => a + ", " + i) + "]";
        }
        else json = _jsonSerializer.Serialize(output);
        _outputWriter.Write(mimeType, json);
    }

    private string SerializeExpando(object expando)
    {
        return "{" + (expando as IDictionary<string, object>)
            .Select(x => string.Format("\"{0}\": {1}", x.Key, _jsonSerializer.Serialize(x.Value)))
            .Aggregate((a, i) => a + ", " + i) + "}";
    }
}

QueryController.cs

public List<ExpandoObject> post_query(QueryRequest request)
{
    var results = new List<ExpandoObject>();
    using (var connection = new OdbcConnection("DSN=QuickBooks Data"))
    {
        connection.Open();
        using (var reader = new OdbcCommand(request.query, connection).ExecuteReader())
        {
            while (reader.Read())
            {
                var result = new ExpandoObject() as IDictionary<string, object>;
                if (reader.FieldCount > 0)
                    for (var i = 0; i < reader.FieldCount; i++) 
                        result[reader.GetName(i)] = reader[i];
                results.Add((ExpandoObject)result);
            }
        }
    }
    return results;
}

request.json

{ query: 'SELECT CompanyName, Contact, Phone FROM Customer' }

response.json

[
    { "CompanyName": "Yada", "Contact": "Yada", "Phone": "Yada" }, 
    { "CompanyName": "Yada", "Contact": "Yada", "Phone": "Yada" }
    ...
]