Search for singleton tags on questions

Question

Is there any way to search for questions that have a specific tag and only that lonely tag?

In other words, I'd like to be able to do something like the following to find questions that have a single tag and no other:

[mytag] tagcount:1

This would be very useful for tag cleanup situations to be able to do house-cleaning before nuking a tag.

Answer 1

I took the query in this other answer and cleaned it up a bit, making it more generic:

Select Top 5000 Id As [Post Link], CreationDate
From Posts
Where Tags = Lower('<##Tag##>')
Order By CreationDate Desc

SEDE query.

Answer 2

This query might help...

https://data.stackexchange.com/programmers/query/81422

It is specifically for Programmers but you can use it to search for questions with only a specific tag.

Answer 3

Using the API, you can find all questions that have a certain tag, then filter out the ones that have more than one tag. Here is a demonstration that searches for questions tagged solely with puncture on Bicycles:

var tag = "puncture";
var site = "bicycles";

var url = 'http://api.stackexchange.com/2.1/questions?sort=activity&callback=?';

var h3 = $('h3 span');

// Retrieve data
(function gather(cp, object) {
    if (typeof object === "undefined" || object.has_more) {
        $.getJSON(url, {
            site: site,
            tagged: tag,
            page: ++cp,
            key: "awn3X8U)9erzSfhBhqSF4A((",
            filter: "!BGS1(RNaQD-DYnwoUQeh2eZDaLm__P"
        }, function (data) {
            h3.html("(" + cp + " pages)")
            if (object) {
                data.items = data.items.concat(object.items);
            }
            gather(cp, data);
        });
    } else {
        display(object);
    }
})(0)

// Display data
function display(data) {
    var data = data.items;
    data = data.filter(function (v, i, A) {
        return v.tags.length == 1;
    });
    $.each(data, function (i, v) {
        var li = $('<li/>');
        var a = $('<a/>').attr('href', this.link).text(this.title);
        $('#results').append(li.append(a));
    });
    var heading = $('<h3/>').html('Total: ' + data.length);
    $('#results').prev().replaceWith(heading);
}

Answer 4

Fwiw, if you want to find any question with just one tag, regardless of the tag, you can use a query like this:

SELECT TOP 50
  Id [Post Link], Tags, *
FROM
  Posts
WHERE
  LEN(Tags) - LEN(REPLACE(Tags, '<', '')) = 1 -- # of <'s = # of tags
ORDER BY
  CreationDate DESC

An alternate trick in the case of just one tag is Tags NOT LIKE '%><%'.