how to return selected query in json format in asp.net web formsRSS

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Last post May 11, 2020 05:45 AM by Sean Fang

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uniservice3
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303 Points

255 Posts

how to return selected query in json format in asp.net web forms

May 08, 2020 03:04 PM|uniservice3|LINK

Hi
Dear friends, I want to present the report that I take from the database and put in the datatable in the form of json in the web service, but I don't know how to do this.

in asp.net webforms

for example when my report is like below

id name email

1 amir un@gmail.com

2 zahra am@gmail.com

....

i want to change this report to json format and return it for web users by web service

Sean Fang

Participant

1110 Points

299 Posts

Re: how to return selected query in json format in asp.net web forms

May 11, 2020 05:45 AM|Sean Fang|LINK

Hi, uniservice3

Based on your description, I suggest you could do like this, please refer to the following example:

Foreground code:

<body>

    <form id="userlist_form" runat="server">

        <div>

            <button id="getUserBtn" type="button">get info</button>

            <br />

            <label id="info"></label>

        </div>

    </form>

    <script src="Scripts/jquery-3.4.1.js" type="text/javascript"></script>

    <script>

        $(document).ready(function () {

            $("#getUserBtn").click(function () {

                $.ajax({

                    url: "getUserListService.asmx/getUserList",

                    type: "POST",

                    data: null,

                    contentType: "application/json; charset=utf-8",

                    dataType: "json",

                    success: function (data) {

                        if (data.d != null) {

                            $("#info").html(data.d);

                        } else {

                            $("#info").html("There is no data");

                        }

                    }

                });

            });

        });

    </script>

</body>

Behind code(web service):

// datatable to Json

        public string DataTableToJSON(DataTable table)

        {

            string JSONString = string.Empty;

            JSONString = JsonConvert.SerializeObject(table);

            return JSONString;

        }

         

        [WebMethod]

        public String getUserList()

        {

            String jsonStr;

            DataTable dt = new DataTable();

            String conStr = "Server=.;Database=TestDB;Trusted_Connection=True";

            using (SqlConnection con = new SqlConnection(conStr))

            {

                String sql = "select * from users";

                SqlDataAdapter sda = new SqlDataAdapter(sql, con);

                sda.Fill(dt);

                if (dt.Rows.Count > 0)

                {

                    jsonStr = DataTableToJSON(dt);

                    return jsonStr;

                }else

                {

                    return null;

                }

            }

        }

Result:

Page display:

Response:

I would like to know if this can help you meet your needs.

If it is another requirement, could you please describe it in detail?

Best regards,

Sean

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