{% include anchor.html edit="true" title="Document revisions diff" hash="revisions_diff" %} 

{% highlight js %}
db.revsDiff(diff, [callback])
{% endhighlight %}

Given a set of document/revision IDs, returns the subset of those that do not correspond
to revisions stored in the database. Primarily used in replication.

#### Example Usage:

{% include code/start.html id="revsdiff1" type="callback" %}
{% highlight js %}
db.revsDiff({
  myDoc1: [
    "1-b2e54331db828310f3c772d6e042ac9c",
    "2-3a24009a9525bde9e4bfa8a99046b00d"
  ]
}, function (err, result) {
  if (err) { return console.log(err); }
  // handle result
});
{% endhighlight %}
{% include code/end.html %}

{% include code/start.html id="revsdiff1" type="async" %}
{% highlight js %}
try {
  var result = await db.revsDiff({
    myDoc1: [
      "1-b2e54331db828310f3c772d6e042ac9c",
      "2-3a24009a9525bde9e4bfa8a99046b00d"
    ]
  });
} catch (err) {
  console.log(err);
}
{% endhighlight %}
{% include code/end.html %}

{% include code/start.html id="revsdiff1" type="promise" %}
{% highlight js %}
db.revsDiff({
  myDoc1: [
    "1-b2e54331db828310f3c772d6e042ac9c",
    "2-3a24009a9525bde9e4bfa8a99046b00d"
  ]
}).then(function (result) {
  // handle result
}).catch(function (err) {
  console.log(err);
});
{% endhighlight %}
{% include code/end.html %}

#### Example Response:
{% highlight js %}
{
  "myDoc1": {
    "missing": ["2-3a24009a9525bde9e4bfa8a99046b00d"]
  }
}
{% endhighlight %}