Check duplicate values from database on button click event

Question

I have a requirement, where I want to check whether user is not inserting the same Project, Survey No again and again.

It should fire an alert if it enters the same combination twice on button click

Here is my HTML:-

<td class="label">
                    Project :
                </td>
                <td class="field" style="width: 10%;">
                    <asp:DropDownList ID="ddlProject" runat="server" Width="80%" AutoPostBack="true"
                        OnSelectedIndexChanged="ddlProject_SelectedIndexChanged">
                        <asp:ListItem Value="0">--Select--</asp:ListItem>
                    </asp:DropDownList>
                </td>
                <td class="label">
                    Survey No :
                </td>
                <td class="field">
                    <asp:TextBox ID="txtSurvey1" runat="server" Width="80%" ReadOnly="true"></asp:TextBox>
                </td>

I tried the below link, but it was not for the combination. It was just for one textbox value, So it was not working in my case.

check duplicate data with javascript

Kindly let me know how to deal with the combination part

@Mysterio11: yes, for the checking the combination of two values. — Nad, Sep 01 '16 at 07:02

Sujit.Warrier · Accepted Answer · 2016-09-01T08:51:07.523

-1

I have made a few changes to the answer linked by you

    var projval=$('#ddlProject').val();
    var survey=$('#txtSurvey1').val();
    $.ajax({
     type: "POST",
     url: "YourPage.aspx/DoesDataExist",
    data: JSON.stringify({
        proj :projval, // the names of the properties must match with the parameters in the backend function
        surv :survey
       }),
    contentType: "application/json; charset=utf-8",
    dataType: "json",
     success: function(msg) {
    if(msg.d) {
        // This is a duplicate, alert user with message
        // Block the server-side click from happening with return false;
        return false;
      }
   }
  });

this is the backend webservice

  [WebMethod]
  public static bool DoesDataExist(string proj, string surv )
  {
      SqlCommand commandrepeat1 = new SqlCommand("Select * from table where project="+proj+" and Survey="+surv+" ");
      commandrepeat1.Connection = objconnection;
      objconnection.Close();
      objconnection.Open();
      SqlDataReader drmax1;
      drmax1 = commandrepeat1.ExecuteReader();
      drmax1.Read();
      if (drmax1.HasRows)
      {
          objconnection.Close();
          return true;
      }

      objconnection.Close();
      return false;
}

edited Sep 01 '16 at 08:51

answered Sep 01 '16 at 07:11

Sujit.Warrier

2,815
2
28
47

let me try and check with your answer :) – Nad Sep 01 '16 at 07:12
I am getting error as **Microsoft JScript runtime error: Object expected** at line `var projval=$("#ddlProject").val();` – Nad Sep 01 '16 at 07:23
replace $("#ddlProject").val() with $('<%="#"+ddlProject.ClientId%>') and try – Sujit.Warrier Sep 01 '16 at 07:55
i resolved that error, but now getting error as **Microsoft JScript runtime error: Object doesn't support this property or method** – Nad Sep 01 '16 at 08:01
tell me have you included the jquery library? – Sujit.Warrier Sep 01 '16 at 08:01
yes, here it is `` – Nad Sep 01 '16 at 08:02
this error usually comes if you have not included jquery properly or if you have done it twice – Sujit.Warrier Sep 01 '16 at 08:25
if I take `data: "{'codeValue': $('#txtSurvey1').val()}",` it does not gives me the error – Nad Sep 01 '16 at 08:43
stringify of JSON.stringify.should be lower case. it was a mistake. It was upper case S before – Sujit.Warrier Sep 01 '16 at 08:52
now, I am getting error as `The connection is closed` . :( – Nad Sep 01 '16 at 10:00
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/122383/discussion-between-mysterio11-and-stack). – Sujit.Warrier Sep 01 '16 at 10:04
I am on chat, please come their. we are almost near to my solution – Nad Sep 01 '16 at 10:28

Check duplicate values from database on button click event

1 Answers1