Question

I am using Jqgrid to display my data into jqgrid using web services in asp.net…but it is loading only when I am giving limit in the query.If I want to load all the data using second commneted query in the code then its not loading and giving error “”Message”:”Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.”

Here is my entire Module Architecture…

index.aspx page…

<script type="text/javascript">
    $(function () {
        $("#table").jqGrid({
            datatype: function (pdata) { getData(pdata); },
            height: 500,
            colNames: ['username', 'ordinal', 'authcode', 'extension', 'trunk', 'dialnumber', 'dialdate', 'dialtime', 'duration', 'destination', 'price', 'toc'],
            colModel: [
                    { name: 'username', width: 100, sortable: true, align: 'center' },
                    { name: 'ordinal', width: 100, sortable: true, align: 'center' },
                    { name: 'authcode', width: 100, sortable: true },
                    { name: 'extension', width: 100, sortable: true, align: 'center' },
                    { name: 'trunk', width: 100, sortable: true, align: 'center' },
                    { name: 'dialnumber', width: 100, sortable: true, align: 'center' },
                    { name: 'dialdate', width: 100, sortable: true, align: 'center' },
                    { name: 'dialtime', width: 100, sortable: true, align: 'center' },
                    { name: 'duration', width: 100, sortable: true, align: 'center' },
                    { name: 'destination', width: 100, sortable: true, align: 'center' },
                    { name: 'price', width: 100, sortable: true, align: 'center' },
                    { name: 'toc', width: 100, sortable: true, align: 'center' }
                ],
            rowNum: 100,
            rowList: [100, 200, 300],
            pager: '#UsersGridPager',
            sortname: 'username',
            sortable: true,
            viewrecords: true,
            sortorder: 'asc',
            shrinkToFit: false,
            rownumbers: true,
            loadtext: 'Loading..'

        });
        jQuery("#table").jqGrid('navGrid', '#UsersGridPager', { add: false, edit: false, del: false, search: true, refresh: true });
    });


    function getData(pData) {
        $.ajax({
            type: 'POST',
            contentType: "application/json; charset=utf-8",
            url: '<%= ResolveClientUrl("~/WebService.asmx/GetListOfPersons") %>',
            data: '{}',
            dataType: "json",
            success: function (data, textStatus) {
                if (textStatus == "success")
                    ReceivedClientData(JSON.parse(getMain(data)).rows);
            },
            error: function (data, textStatus) {
                alert('An error has occured retrieving data!');
            }
        });
    }


    function ReceivedClientData(data) {
        var thegrid = $("#table");
        thegrid.clearGridData();
        for (var i = 0; i < data.length; i++)
            thegrid.addRowData(i + 1, data[i]);
    }


    function getMain(dObj) {
        if (dObj.hasOwnProperty('d'))
            return dObj.d;
        else
            return dObj;
    }
</script>

JsonHelper.cs file

// Convert Object to Json String
// <param name="obj">The object to convert</param>
// <returns>Json representation of the Object in string</returns>

public static string ToJson(object obj)
{
    return Newtonsoft.Json.JsonConvert.SerializeObject(obj);
}

public static List<Person> GetPersons()
{
    List<Person> persons = new List<Person>();
    string connectionString = "Server=localhost;Port=3306;Database=projecttt;UID=root;Pwd=techsoft;pooling=false";

    MySqlConnection conn;
    conn = new MySqlConnection(connectionString);
    conn.Open();

    string s = "SELECT username,ordinal,authcode,extension,trunk,dialnumber,dialdate,dialtime,duration,destination,price,toc FROM processeddata_table order by username limit 0,200";
   // string s = "SELECT username,ordinal,authcode,extension,trunk,dialnumber,dialdate,dialtime,duration,destination,price,toc FROM processeddata_table ";
    MySqlCommand cmd = new MySqlCommand(s,conn);

    cmd.ExecuteNonQuery();

    using (MySqlDataReader dr = cmd.ExecuteReader())
    {

        while (dr.Read())
        {
            persons.Add(new Person()
            {
                username = Convert.ToString(dr["username"]),
                ordinal = Convert.ToString(dr["ordinal"]),
                authcode = Convert.ToString(dr["authcode"]),
                extension = Convert.ToString(dr["extension"]),
                trunk = Convert.ToString(dr["trunk"]),
                dialnumber = Convert.ToString(dr["dialnumber"]),
                dialdate = Convert.ToString(dr["dialdate"]),
                dialtime = Convert.ToString(dr["dialtime"]),
                duration = Convert.ToString(dr["duration"]),
                destination = Convert.ToString(dr["destination"]),
                price = Convert.ToString(dr["price"]),
                toc = Convert.ToString(dr["toc"])

            });
        }

    }

    return persons;
}

}

PagedList.cs File

IEnumerable _rows;
int _totalRecords;
int _pageIndex;
int _pageSize;
object _userData;

public PagedList(IEnumerable rows, int totalRecords, int pageIndex, int pageSize, object userData)
{
    _rows = rows;
    _totalRecords = totalRecords;
    _pageIndex = pageIndex;
    _pageSize = pageSize;
    _userData = userData;
}

public PagedList(IEnumerable rows, int totalRecords, int pageIndex, int pageSize)
    : this(rows, totalRecords, pageIndex, pageSize, null)
{
}

public int total { get { return (int)Math.Ceiling((decimal)_totalRecords / (decimal)_pageSize); } }

public int page { get { return _pageIndex; } }

public int records { get { return _totalRecords; } }

public IEnumerable rows { get { return _rows; } }

public object userData { get { return _userData; } }

public override string ToString()
{
    return Newtonsoft.Json.JsonConvert.SerializeObject(this);
}

}

webservices.cs

[WebMethod]
[ScriptMethod]

public string GetListOfPersons()
{
    List<Person> persons = JsonHelper.GetPersons();
    return Newtonsoft.Json.JsonConvert.SerializeObject(new PagedList(persons, persons.Count, 1, persons.Count));
}

}

Person.cs

public string username { get; set; }
public string ordinal { get; set; }
public string authcode { get; set; }
public string extension { get; set; }
public string trunk { get; set; }
public string dialnumber { get; set; }
public string dialdate { get; set; }
public string dialtime { get; set; }
public string duration { get; set; }
public string destination { get; set; }
public string price { get; set; }
public string toc { get; set; }

Plz guys Help me .THanx in advance..

Answer 1

Why are you using ExecuteNonQuery() for select ? try ExecuteReader() method.

See this :- Question on MaxJsonLength

For local pagination loadonce: true can be used but still you will get the same error as you are trying to load too much data which is not advised. Also, ajax requests are used to handle small amount of data