Change an existing object in an array but still preserve key uniqueness - mongodb

Question

I have a document:
{ 'profile_set' :
[
{ 'name' : 'nick', 'options' : 0 },
{ 'name' : 'joe', 'options' : 2 },
{ 'name' : 'burt', 'options' : 1 }
]
}
If I want to add new object to the profile_set only if the name of the object isn't already taken, regardless of the options, I can qualify my update with a query object that prevents the update if the name is already present in profile_set. In the shell:
db.coll.update(
{_id: id, 'profile_set.name': {$ne: 'nick'}},
{$push: {profile_set: {'name': 'nick', 'options': 2}}})
So this will only perform the $push for a doc with a matching _id and where there isn't a profile_set element where name is 'nick'.
Question But if I later need to change Nick's name (and maybe his options too...), that is change an existing array object, not add a new one. Is there a way to do that in one atomic update operation that still honor the unique constraint of name?

Answer 1

There are two conditions, I think:
var newName = "somename";
var oldName = "nick";
var newOption = 3;
// if not change the name
db.coll.update({
_id : id,
'profile_set.name' : oldName
}, {
$set : {
"profile_set.$.options" : newOption
}
});
// if change the name
db.coll.update({
_id : id,
$and : [ {
'profile_set.name' : {
$ne : newName
}
}, {
'profile_set.name' : oldName
} ]
}, {
$set : {
"profile_set.$.name" : newName,
"profile_set.$.options" : newOption
}
});