Jquery Ajax JSON data read is not working - asp.net

Question

I'm trying to retrieve data from SQL server DB and convert it to JSON and try to show the json data using JQuery Ajax function, here is the C# code,
C#
public String GetData()
{
try
{
String strjson;
string connectionstring = ConfigurationManager.ConnectionStrings["ConString"].ConnectionString;
SqlConnection Con = new SqlConnection(connectionstring);
DataSet DS = new DataSet();
String CmdText = "Select Compname,compadd1,compadd2,compemail from company where compid=#cmpid";
SqlCommand cmd = new SqlCommand(CmdText, Con);
cmd.Parameters.Add("#cmpid", SqlDbType.Int).Value = 22;
Con.Open();
SqlDataAdapter DA = new SqlDataAdapter(cmd);
DA.Fill(DS);
DataTable dTable = DS.Tables[0];
strjson = GetJSONString(dTable);
Con.Close();
return strjson;
}
catch (Exception ex)
{
throw new System.Exception("Error In Get Data" + ex.Message);
}
}
the GetJSONString(dTable) function working fine, here is the JQuery code,
jQuery & HTML
<form id="form1" runat="server">
<div>
<h1>JSON Sample</h1>
<button id="getdata">Get Data</button>
<div id="company"></div>
<%-- <asp:Button ID="aspbutton" runat="server" Text=".Net Call" OnClick="btnOn_Click" />
<asp:GridView runat="server" ID="grdview"></asp:GridView>--%>
</div>
<script type="text/javascript">
$(document).ready(function () {
$("#getdata").click(function () {
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
data: "",
url: "Default.aspx/GetData",
dataType: "json",
success: function (data) {
alert(data.d);
$("#company").html(data.d);
}
});
});
});
</script>
</form>
I have included the jQuery file, please let me know if I have made any mistake,
EDITED :GetJSONString added
public static string GetJSONString(DataTable Dt)
{
string[] StrDc = new string[Dt.Columns.Count];
string HeadStr = string.Empty;
for (int i = 0; i < Dt.Columns.Count; i++)
{
StrDc[i] = Dt.Columns[i].Caption;
HeadStr += "\"" + StrDc[i] + "\" : \"" + StrDc[i] + i.ToString() + "¾" + "\",";
}
HeadStr = HeadStr.Substring(0, HeadStr.Length - 1);
StringBuilder Sb = new StringBuilder();
Sb.Append("{\"" + Dt.TableName + "\" : [");
for (int i = 0; i < Dt.Rows.Count; i++)
{
string TempStr = HeadStr;
Sb.Append("{");
for (int j = 0; j < Dt.Columns.Count; j++)
{
switch (Dt.Columns[j].DataType.ToString())
{
case "System.DateTime":
DateTime cv = (DateTime)Dt.Rows[i][j];
TempStr = TempStr.Replace(Dt.Columns[j] + j.ToString() + "¾", cv.Year + "," + (cv.Month - 1) + "," + cv.Day + "," + cv.Hour + "," + cv.Minute + "," + cv.Second + "," + cv.Millisecond);
break;
case "System.Boolean":
TempStr = TempStr.Replace(Dt.Columns[j] + j.ToString() + "¾", Dt.Rows[i][j].ToString().ToLower());
break;
default:
string str = Dt.Rows[i][j].ToString();
str = str.Replace("\n", "\\\\n");
str = str.Replace("\\", "\\\\\\\\");
str = str.Replace("\"", "ppp");
str = str.Replace("'", "\\\'");
str = str.Replace("\r", "\\\\r");
TempStr = TempStr.Replace(Dt.Columns[j] + j.ToString() + "¾", str);
break;
}
}
Sb.Append(TempStr + "},");
}
Sb = new StringBuilder(Sb.ToString().Substring(0, Sb.ToString().Length - 1));
Sb.Append("]}");
return Sb.ToString();
}
I added error: section in Ajax call, now getting the error "error; [object Object]"

Answer 1

Finally, I found what was the issue, I have to add "[WebMethod()]" declaration just before the asp.net function. For example,
[WebMethod()]
public static string GetData()
{
try
{
string strjson;
string connectionstring = ConfigurationManager.ConnectionStrings["ConString"].ConnectionString;
SqlConnection Con = new SqlConnection(connectionstring);
DataSet DS = new DataSet();
String CmdText = "Select Compname,compadd1,compadd2,compemail from aas_company where compid=#cmpid";
SqlCommand cmd = new SqlCommand(CmdText, Con);
cmd.Parameters.Add("#cmpid", SqlDbType.Int).Value = 22;
Con.Open();
SqlDataAdapter DA = new SqlDataAdapter(cmd);
DA.Fill(DS);
DataTable dTable = DS.Tables[0];
strjson = GetJSONString(dTable);
Con.Close();
return strjson;
}
catch (Exception ex)
{
throw new System.Exception("Error In Get Data" + ex.Message);
}
}