Mongooose query where ObjectId is null?
How can I find the document executing .findOne
where the field is not specified ObjectId
? I can't seem to find if I should be looking in null
or undefined
or something else.
In the example below, I'm trying to find a document where the "email" value is known but the userId hasn't been set yet:
var joinRequest = new mongoose.Schema({
email: { type: String, unique: true, lowercase: true, trim: true },
code: { type: String, uppercase: true, trim: true, select: false },
lastSent: { type: Date },
userId: { type: mongoose.Schema.Types.ObjectId, select: false }
});
Again, can the field ObjectId
be null? Should I be using it String
here?
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A little about undefined
in the context of MongoDB
Properties with a value are undefined
not saved. So the next property a
won't
db.insert({a : undefined})
However, for arrays, the values are undefined
converted tonull
db.insert({a : [undefined]}) //stores {a : [null]}
Also undefined
has strange behavior when used as a condition
db.users.find({a : undefined}) //finds everything
db.users.findOne({a : undefined}) //always returns the first document (which is a problem for you)
db.users.update({a : undefined}, {a : true}) //only updates documents with no a property
So I would avoid using it undefined
and probably pretend it doesn't even exist. Use instead null
as it is stored and sometimes cannot be dropped as a condition.
So for example
db.users.insert({email : "email@domain.com", userID : null});
db.users.findOne({email : "email@domain.com", userID : null});
If you choose to use undefined, but do it like this
db.users.insert({email : "email@domain.com"});
db.users.findOne({email : "email@domain.com", userID : { exists : false }}); //works for null as well
http://docs.mongodb.org/manual/reference/operator/query/exists/
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