Delete duplicate list items

Sounds like a doable workflow, when it starts on item creation it will do the query and save any field, like ID into a collection. Then do a collection operation to count the items. Then have a condition to see if greater than 0, if it is, then delete the current item. Doing so by using the delete item action where ID is equal to the common reference to the current item's ID.

Forms do not seem to be able to do this for you as of yet. You can add a validation to the save button to lookup items and if the count is greater than one to say the form is not valid and display the message that you already created an item. The problem I see right now is, you cannot filter the lookup by the current user for some reason. If you can get that working, let me know how, I need to use it.

Hi Rency,

My preference would be to remove the option to create another item, if one already exists.

If you are open to using JavaScript you can do the following.

1. On the list view page add a CEWP.
2. Select the CEWP and 'Edit HTML Source'.
3. Add the Style and JavaScript below into the CEWP.
4. Update the 'listTitle' to the name of your list.

Default hide the 'Add New Item' link, this reduces flicker.

<style>

    #Hero-WPQ2 {display: none;}

</style>

User JavaScript to see if user has already created an item in this list.  If not show the 'Add New Item' link.

<script language="javascript" type="text/javascript">

    var listTitle = "NAMEOFYOURLISTHERE", currentUser, list, listItems;

    // Invoke getData function.

    ExecuteOrDelayUntilScriptLoaded(getData, "sp.js");

    function getData() {

        var ctx = new SP.ClientContext.get_current();

        // Get current user.

        this.currentUser = ctx.get_web().get_currentUser();

        ctx.load(this.currentUser);

        // Get the URL for the default new item form.

        this.list = ctx.get_web().get_lists().getByTitle(this.listTitle);

        ctx.load(this.list, "DefaultNewFormUrl");

        // Get the list item collection.

        var caml = new SP.CamlQuery();

        this.listItems = this.list.getItems(caml);

        ctx.load(this.listItems, "Include(Author)");

        ctx.executeQueryAsync(

             Function.createDelegate(this, success),

             Function.createDelegate(this, failure)

        );

    }

    function success(sender, args) {

        if ((this.currentUser) && (this.listItems)) {   

            var userName = this.currentUser.get_title();

            var hasSubmitted = false;

            // Enumerate over the list items.

            var itemsEnumerator = this.listItems.getEnumerator();

            while (itemsEnumerator.moveNext()) {

                var item = itemsEnumerator.get_current();

                // If the list has an item where the Author is the current user...

                if (userName == item.get_item("Author").get_lookupValue()) {

                    // then the current user has voted.

                    hasSubmitted = true;

                    break;

                }

            }

        }

        if(hasSubmitted) { $get("Hero-WPQ2").style.display = "none"; } // Keep add link hidden.

        else { $get("Hero-WPQ2").style.display = "block"; }  // Show add link.

    }

    function failure(sender, args) { alert(args.get_message());    }   

</script>

What this does:

On page load it check if the current accessing user has already submitted an item to the named list.  If so the 'Add New Item' button is hidden.

Hope this helps.

Cheers,

Barry.

Make sure the list webpart is on top of the page. Changing the list page changes how the ribbon can work with the contents.

I only have access to test this within SP2010 at the moment.  Did you update the following line to contain the name of your list?

var listTitle = "NAMEOFYOURLISTHERE"

In the delete item, have it as ID equals (current item ID). It should be a workflow context reference.

I got it working!!! Thank you soooo much Andrew! I had to use List Lookup to find the Current Item ID

Thank you everyone for trying to help me, you are all the best and I am learning so much from each and every one of you

Best community ever!

Thank you Ajay!

I attached a exported workflow of this if anyone wants to use it.

Try importing this attached workflow. Your "run if" action is probably not set up properly.