how to get a sclar from DB using ajax.jquery

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hiiii , i am begginer in jquery.ajax , i try to get a scalar value from DB but it alert undefined , i don't know why . below is HTML page

HTML

<script src="jquery-1.11.1.min.js"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $('#btn1').click(function () {
            $.ajax({
                type: "POST",
                url: "WebForm1.aspx/getdep",
                data: '{x:1}',
                datatype: "json",
                contentType: "application/json charset-utf-8",
                success: function (data) {
                    alert(data.d);
                },
            });
        });
    });
</script>

below is .cs page

C#

public partial class WebForm1 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    [webmethod]
    public string getdep(int x)
    {
        using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["myconnection"].ConnectionString))
        {

            SqlCommand cmd = new SqlCommand("select depname from dep where depid="+x, connection);
            connection.Open();
            string result = cmd.ExecuteScalar().ToString();
            return result;
        }
    }
}

Posted 17-Sep-14 5:05am

Hercal

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Comments

ZurdoDev 17-Sep-14 11:18am

Debug it and you should find quickly what is happening.

Hercal 17-Sep-14 11:28am

how :D ?

ZurdoDev 17-Sep-14 11:54am

Put a breakpoint.

Hercal 17-Sep-14 12:11pm

i know , but i mean how to debug [ client side code ]

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Herman<T>.Instance · Answer 1 · 2014-09-17T05:18:00

Solution 1

ExecuteScalar() is of type object:
see here[^]
so:

C#

[webmethod]
    public object getdep(int x)
    {
        using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["myconnection"].ConnectionString))
        {

            SqlCommand cmd = new SqlCommand("select depname from dep where depid="+x, connection);
            connection.Open();
            var result = cmd.ExecuteScalar();
            return result;
        }
    }

Posted 17-Sep-14 5:18am

Herman<T>.Instance

Comments

Hercal 17-Sep-14 11:28am

but i parse it into string :- string result = cmd.ExecuteScalar().ToString();

Herman<T>.Instance 17-Sep-14 16:40pm

you call:
string theAnswer = getdep(<yourint>).ToString();

ZurdoDev 17-Sep-14 11:55am

No. He wants to return a string. ExecuteScalar().ToString() will work.

Hercal 17-Sep-14 12:10pm

i try it , it doesn't work , it also alert undefined ,...........be noted that when i execute the same code in page load using ExecuteScalar().ToString() and without jquery.ajax , it works.