Displaying only duplicate items based on column value (e.g. Title)

Question

Trying to figure out a way to

Create a list of duplicate list items based on a column contained in such a list. In my example, it is the title column.

First, I was thinking that I could create a group view, but the issue with that is that it also displays items that are not duplicates.

I was thinking that SPServices could be helpful, but I can't figure out a way to display only items that are duplicate. Any assistance would be greatly appreciated.

Answer 1

Note:

in June 2017, Microsoft disabled the use of JavaScript in a Calculated Column

That means given answers may not apply for newer SharePoint versions

For long explanation and work arounds see:
June 13th 2017 Microsoft blocked handling HTML markup in SharePoint calculated fields - how to get the same functionality back

---

**Original answer:**

• You want to record the Title for each displayed row
• then after all are displayed, hide the ones not having dublicate titles

Client Side Rendering or a jQuery script would be the obvious solutiuon.

Alternative is to jam that code into every ListItem as a Calculated Column.

Biggest benefit, it just executes anywhere it is displayed, no need for loading jQuery, no need for setting JSLinks on every webpart.

Paste the Formula in a Calculated Column, set datatype to Number and include it as last column in a View:

="<img  src=/_layouts/images/blank.gif onload=""{"
&"var rowvalue='count_" & [Title] & "'"
&",counters=window.counters=window.counters||{};"
&"var TR=this;while(TR.tagName!='TR'){TR=TR.parentNode}"
&"counters[rowvalue]=counters[rowvalue] || 0;"
&"counters[rowvalue]++;"
&"_spYield(function(){"
&"  TR.style.display=counters[rowvalue]>1 ? 'table-row' : 'none'; "
&"},1);"
&"}"">"

• Each item displays a blank IMG to trigger JavaScript code (the SCRIPT tag is disabled by Microsoft)
• You can then built a JavaScript variable with the value you want to check doubles for

Since this code is always executed for every ListItem we need some special bookkeeping of Global variables

• we check if a Global variable (object) exists, use it or declare it (once) as a new object
• we check if the value exists in the global object (a previous occurence) or set the counter to 0
• then always add 1 to the count

At this stage you could hide double values if the counter is >1 .. but you want the reverse, so it is essential we count all items first.

• _spYield (declared in SP.js, but you won't find any blogs or documentation) makes JavaScript execution wait (something not possible out of the box with JavaScript)

We need this wait/delay because IMGs are loaded async, thus this code as well and we want to make sure all ListItems are processed/counted.. a yield/Wait of 1 millisecond seems to be enough

So once all ListItems are counted they execute their own function

• the executed function sets the display based on the counter (for that rowvalue).

You could also not hide rows add apply coloring here:

&"  TR.style.bacgrkound=counters[rowvalue]>1 ? 'lightcoral' : 'beige'; "

.

There are some Pros & Cons to this method. Read: https://www.365csi.nl/vm365com/#/How

iCC