ServiceStack.Text：将DataSet序列化为json

Question

I am having a trouble serializing a dataset to json using ServiceStack.Text (from Nuget.org). I am using the latest stable build 4.0.50 and VS 2015 . I keep getting

Process is terminated due to StackOverflowException

My code:

using System;
using System.Data;
using System.Data.SqlClient;
using ServiceStack.Text;

namespace TestServiceStackText
{
    class Program
    {
        static void Main(string[] args)
        {
            string ConnectionString = @"Server=MyServer; Database=NORTHWND; User Id=SomeUser; Password=SomePassword;";
            string SqlQuery = @"SELECT TOP 1 * FROM [NORTHWND].[dbo].[Customers]";

            // Create new dataset instance
            DataSet dataset = new DataSet();

            // Fill it with a little data: 1 table, 1 row
            using (var conn = new SqlConnection())
            {
                using (var da = new SqlDataAdapter())
                {
                    using (da.SelectCommand = conn.CreateCommand())
                    {
                        da.SelectCommand.CommandText = SqlQuery;
                        da.SelectCommand.Connection.ConnectionString = ConnectionString;
                        da.Fill(dataset);
                    }
                }
            }

            // Serialize to json: exception occurs here
            string json = TypeSerializer.SerializeToString<DataSet>(dataset);
            Console.WriteLine("Dataset serialized to json:\n {0}", json); 

            // Deserialize to DataSet
            DataSet ds = TypeSerializer.DeserializeFromString<DataSet>(json);
            Console.WriteLine("Name: {0}, Nr. of Tables: {1}", ds.DataSetName, ds.Tables.Count);
        }
    }
}

Suggestions anybody?

Answer 1

None of ServiceStack's text serializers have explicit support for DataSet's which are a horrible type for serialization.

Micro ORM's like OrmLite ends up being much cleaner and easier to use which maps to clean POCO's that are ideal for serialization , eg the equivalent code for your above query is:

var customers = Db.Select<Customer>(q => q.Take(1));

var json = customers.ToJson();
var dto = json.FromJson<Customer>();

Or if you don't want to create a Customer type you can use OrmLite's dynamic API's to map to a lose typed List of objects:

var list = Db.Select<List<object>>(
   "SELECT TOP 1 * FROM [NORTHWND].[dbo].[Customers]");

Or a Dictionary:

var dict = Db.Select<Dictionary<string,object>>(
   "SELECT TOP 1 * FROM [NORTHWND].[dbo].[Customers]");

Checkout the northwind.servicestack.net project for code examples of using OrmLite and AutoQuery to query the Northwind dataset.

In summary, you'll have a lot less issues if you use clean POCOs instead of DataSets which are supported in every serializer, are much smaller and faster than DataSet's, you can also serialize POCO's or loose-typed Dictionary's to CSV with ServiceStack.Text:

var csv = customers.ToCsv();
var csv = dict.ToCsv();