Why does my controller action add 2 new records instead of one

Question

I have a simple razor view with a button that is supposed to add a new record to a table in my SQL DB. The button has attached an ajax function that calls the controller.

I tried two different controllers; both controllers work but add 2 new records instead of one. See below code snippets:

Button click event in razor view

$('#addLike')
    .click(function (e) {
        var proposalId = 12;
        var url = "@Url.Action("AddLike", "Proposal")/?proposalId=" + proposalId;
            $.ajax({
                type: "POST",
                url: url,
                dataType: "json",
                traditional: true,
                success: function(response) {
                    window.location.href = actions.common.proposals;
                }
            });
    });

Class model

public class Proposal_Likes
{
    public int? Proposal_Id { get; set; }
    public int Id  { get; set; } (... Identity, DatabaseGenerated)
}

Controller

public ActionResult AddLike(int proposalId)
{
    var proposal_Like =  new Proposal_Likes
    {
        Proposal_Id = proposalId
    };

    UnitOfWork.InsertOrUpdate(proposal_Like);
    UnitOfWork.Commit();

    return Json("Success");
}

alternative Controller

public ActionResult AddLike(int proposalId)
{
        using (SqlConnection con = new SqlConnection(cs))
        {
            using (SqlCommand cmd = new SqlCommand("addProposalLike", con))
            {
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.Add("@propsalId", SqlDbType.Int).Value = proposalId;
                con.Open();
                cmd.ExecuteNonQuery();
            }
        }

    return Json("Success");
}

I have been working on this for almost 2 days, debugged through the entire code but can't find the cause or a clue where to dig deeper. When I execute the SQL stored procedure manually inside SSMS it does add only one record. Any help will be appreciated!

Additional info: No submits, no other buttons on the view

Have you checked if the method is being called twice for some reason? — João Pedro Sousa, Oct 01 '19 at 14:49
Is this of help : https://stackoverflow.com/questions/1751266/asp-net-mvc-action-is-called-twice — PaulF, Oct 01 '19 at 14:53
While debugging: In case of the sql procedure I have not seen any indications that it is called twice. In case of the link procedure it looks like parts of the procedure are called twice ... could not remove it by adapting the code — Manu, Oct 01 '19 at 14:53

score 1 · Accepted Answer · answered Oct 03 '19 at 07:35

I found the cause: With my ajax function I was using a parameter in the url.Action in order to pass it to an ActionResult controller:

$.ajax({
type: "POST"
var url = "@Url.Action("AddLike", "Proposal")/?proposalId=" + proposalId;
...

public ActionResult AddLike(int proposalId)
{ ...}

This caused the controller to be called twice.(Why ... I don't know). When I pass the parameter via the data part of the ajax call

    var url = "@Url.Action("AddLike", "Proposal")";
         $.ajax({
             type: "POST",
             url: url,
             dataType: "json",
             data: {
                 proposalId: 24,
                    },

into a model and the controller

public class ProposalViewModel
{
    public int proposalId { get; set; }
}

public ActionResult AddLike(ProposalViewModel model)
{   var propId = model.proposalId
    ...
}

the controller is called only once as expected.

Why does my controller action add 2 new records instead of one

1 Answers1