How to convert json into datatable?

Question

Does anyone know how to convert a json string into DataTable from asp.net? I came to know about the Deserialize, it needs the class, I just want the datatable as returned. C

Answer 1

Assuming that your JSON string is a list of objects, each object will correspond to a row in the DataTable, viz:

    public DataTable DerializeDataTable()
    {
        const string json = @"[{""Name"":""AAA"",""Age"":""22"",""Job"":""PPP""},"
                           + @"{""Name"":""BBB"",""Age"":""25"",""Job"":""QQQ""},"
                           + @"{""Name"":""CCC"",""Age"":""38"",""Job"":""RRR""}]";
        var table = JsonConvert.DeserializeObject<DataTable>(json);
        return table;
    }

This requires the Json.NET framework.

If your JSON structure is different please post it. Best Regards.

Answer 2

This question is sorta outdated, but someone may be looking for answers, so here it goes. It didn't work with old JSON.NET, but today I upgraded to latest version and viola! It works great.

Have serialized a DataTable into Json back and forth, zero issues! This is an awesome new feature.

Hope it helps others as well. Cheers.

Answer 3

using Newtonsoft.Json;

string json = "[{"clientID":"1788","projectID":"19"},{"clientID":"1789","projectID":"24"},{"clientID":"1790","projectID":"24"},{"clientID":"1790","projectID":"23"},{"clientID":"1790","projectID":"21"}]";

DataTable tester = (DataTable) JsonConvert.DeserializeObject(json, (typeof(DataTable)));

Code for the above method

public object Deserialize(string jsonText, Type valueType)
{
    try
    {
        Newtonsoft.Json.JsonSerializer json = new Newtonsoft.Json.JsonSerializer();

        json.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;
        json.ObjectCreationHandling = Newtonsoft.Json.ObjectCreationHandling.Replace;
        json.MissingMemberHandling = Newtonsoft.Json.MissingMemberHandling.Ignore;
        json.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;

        StringReader sr = new StringReader(jsonText);

        Newtonsoft.Json.JsonTextReader reader = new JsonTextReader(sr);
        object result = json.Deserialize(reader, valueType);
        reader.Close();
        return result;
    }
    catch (Exception ex)
    {
        throw ex;
    }


}

Deserialize your jsonstring to some class

List<User> UserList = JsonConvert.DeserializeObject<User>(jsonString);

Write following extension method to your project

public static DataTable ToDataTable<T>(this IList<T> data)
{
    PropertyDescriptorCollection props =
    TypeDescriptor.GetProperties(typeof(T));
    DataTable table = new DataTable();
    for(int i = 0 ; i < props.Count ; i++)
    {
    PropertyDescriptor prop = props[i];
    table.Columns.Add(prop.Name, prop.PropertyType);
    }
    object[] values = new object[props.Count];
    foreach (T item in data)
    {
    for (int i = 0; i < values.Length; i++)
    {
        values[i] = props[i].GetValue(item);
    }
    table.Rows.Add(values);
    }
    return table;        
}

Call extension method like

UserList.ToDataTable<User>();

Answer 4

I am not sure which JSON library you are using, but you might want to take a look at JSON.NET as there is a converter object type in there called this:

 Newtonsoft.Json.Converters.DataTableConverter
    // Summary:
    //     Converts a System.Data.DataTable to and from JSON.

I have not used this functionality before but you could have a go with it.

Answer 5

It´s simple.

If you are in framework 2.0, you must import json.net (http://json.codeplex.com/) in your project, if your framework is superior, it has json.

The code in vb.net framework 2.0:

Dim Table DataTable

Table = Json.JsonConvert.DeserializeObject(Of DataTable)(Json_string)

That´s all.