create json data with linq query

Hi,

Please refer below code.

C#

protected void Page_Load(object sender, EventArgs e)
{
    int yearP = 2014;
    string jsonData = Jqufunc(2014);
}

public static string Jqufunc(int yearP)
{
    try
    {
        List<Catg_type> categories = new List<Catg_type> { 
        new Catg_type{ Catg_id = 1,Catg_type1="ComputerScience"},
        new Catg_type{ Catg_id = 2,Catg_type1 = "Management"},
        new Catg_type{Catg_id = 3, Catg_type1="Finance"}
    };
        List<Program_type> programTypes = new List<Program_type>
    {
        new Program_type{ Prog_id=1,Prog_name="Bachelors"},
        new Program_type{ Prog_id=2,Prog_name="Masters"}
    };

        List<Year_info> years = new List<Year_info> { 
        new Year_info{ year_id = 1,year = 2014},
        new Year_info{ year_id = 1,year = 2015},
    };

        List<Std_info> students = new List<Std_info> { 
        new Std_info{sid = 1,Catg_id = 1,year_id=1,Prog_id=1},
        new Std_info{sid = 2,Catg_id = 2,year_id=1,Prog_id=1},
        new Std_info{sid = 3,Catg_id = 3,year_id=1,Prog_id=2},
        new Std_info{sid = 4,Catg_id = 3,year_id=1,Prog_id=2},
        new Std_info{sid = 5,Catg_id = 3,year_id=1,Prog_id=2},
        new Std_info{sid = 6,Catg_id = 2,year_id=1,Prog_id=2},
        new Std_info{sid = 7,Catg_id = 2,year_id=1,Prog_id=2},
    };

        string res = "[";
        var b = categories.OrderBy(x => x.Catg_type1);
        foreach (var c in b)
        {
            res += "'" + c.Catg_type1 + "',";
        }
        res = res.Substring(0, res.Length - 1);
        res += "]";

        var allprogs = programTypes;
        string res2 = "[";

        foreach (var pr in allprogs)
        {
            res2 += "{name: '" + pr.Prog_name + "',";
            res2 += "'" + yearP + "',";
            var allcats = categories;
            res2 += "data:";
            var result = (from stdtable in students
                            join catg in categories on stdtable.Catg_id equals catg.Catg_id
                            join prog in programTypes on stdtable.Prog_id equals prog.Prog_id
                            join yea in years on stdtable.year_id equals yea.year_id
                            where yea.year == yearP && prog.Prog_name == pr.Prog_name
                            orderby prog.Prog_name
                            group stdtable by new { catg.Catg_type1, prog.Prog_name, yea.year } into g
                            select new
                            {
                                g.Key.Catg_type1,
                                g.Key.Prog_name,
                                g.Key.year,
                                total_students = g.Count(),
                            });

            string d = string.Empty;
            foreach (var item in b)
            {
                var re = (from rest in result
                            where rest.Catg_type1 == item.Catg_type1
                            select rest).FirstOrDefault();

                if (re != null)
                {
                    d += re.total_students;
                }
                else
                {
                    d += "0";
                }
                d += ",";
            }


            res2 += d.Remove(d.Length - 1);
            res2 += "},";
        }
        res2 = res2.Remove(res2.Length - 1);
        res2 += "]";
        return res + res2;
        //return null;
    }
    catch (Exception exception)
    {
        throw new Exception();

    }

}

public class Std_info
{
    public int sid { get; set; }
    public int Catg_id { get; set; }
    public int Prog_id { get; set; }
    public int year_id { get; set; }
}

public class Catg_type
{
    public int Catg_id { get; set; }
    public string Catg_type1 { get; set; }
}

public class Program_type
{
    public int Prog_id { get; set; }
    public string Prog_name { get; set; }
}

public class Year_info
{
    public int year_id { get; set; }
    public int year { get; set; }
}

I hope this will help you out.