DataTable to Json using jquery

Question

I\'m trying to execute a web service which returns a DataTable with the following piece of code:

$.ajax({  
    type: \"POST\",  
    url: url,  
    data: d         


        

Answer 1

Json.NET has the ability to write DataSets/DataTables to JSON.

http://james.newtonking.com/archive/2008/09/06/dataset-datatable-serialization-with-json-net.aspx

Answer 2

I must admit I'm not hugely surprised - DataTable basically breaks most of the rules of structured data. Why not simply project from the data-table into a typed object? A related question came up earlier... or if you know the schema of the DataTable just do the conversion in C#...

Manually building the JSON might work, but there are a lot of edge-cases to avoid; I'd rather let an existing framework handle it, to be honest.

Answer 3

Easiest way is to use the LINQ to DataSet extensions. First need to create a generic list (SearchSerialResults is just a DTO in this case) from the DataTable using LINQ to DataSet.

var resultItems = (from DataRow dr in _returnedData.AsEnumerable() select new SearchSerialResults {
  ContractLineItem = (int) dr["fldContractLineItemID"],
    SearchItem = (string) dr["Search Item"],
    Customer = (string) dr["Customer"],
    DeviceFound = (string) dr["Device Found"],
    Country = (string) dr["Country"],
    City = (string) dr["City"],
    ContractNumber = (string) dr["Contract Number"],
    QuoteNumber = (string) dr["Quote Number"],
    BeginDate = (string) dr["Begin Date"],
    EndDate = (string) dr["End Date"]
}).ToList();

_returnedData is the DataTable in this case. Step 2 is to do the conversion. In this case, I am returning a Json object for a jqGrid.

var jsonObject = new {
  total = totalPages,
    pageSize,
    records = totalRecords,
    rows = (from SearchSerialResults item in resultItems select new {
      id = item.ContractLineItem,
        cell = new [] {
          item.ContractLineItem.ToString(),
            item.SearchItem,
            item.DeviceFound,
            item.Customer,
            item.ContractNumber,
            item.QuoteNumber,
            item.Country,
            item.City,
            item.BeginDate,
            item.EndDate,
            ""
        }
    }).ToArray()
};
return Json(jsonObject) // for MVC

Answer 4

.Net 3.5 has a JSONSerializer that should be able to handle a datatable. You may want to look at your service code again and try getting it to use that. Also, I put some code together to do it manually in this question.

Answer 5

http://schotime.net/blog/index.php/2008/07/27/dataset-datatable-to-json/

Answer 6

In the end, I've decided to use the JavaScriptSerializer class to convert the DataTable into a JSON string. Unfortunately, this class doesn't work with a DataTable so I converted the DataTable into a list of dictionnaries and pass that list to the JavaScriptSerializer class. It takes only a few lines of code and it works fine.
Example in VB.net:

    Public Function GetJson(ByVal dt As DataTable) As String

        Dim serializer As System.Web.Script.Serialization.JavaScriptSerializer = New System.Web.Script.Serialization.JavaScriptSerializer()
        Dim rows As New List(Of Dictionary(Of String, Object))
        Dim row As Dictionary(Of String, Object)

        For Each dr As DataRow In dt.Rows
            row = New Dictionary(Of String, Object)
            For Each col As DataColumn In dt.Columns
                row.Add(col.ColumnName, dr(col))
            Next
            rows.Add(row)
        Next
        Return serializer.Serialize(rows)
    End Function