NAND operator

[Hylke Bron]

Hello,

 

How can i create an query to simulate the NAND effect?

 

I have tried the following:

 

child.find({
 $not: {
  $and:[
   {"id.grandParent": "3"},
   {"id.parent" : "2"},
   {"id.child" : "0"}
  ]
 }
});

But this query says MongoError: invalid operator: $and.

 

What i am trying is to find all children, except that particular child that has this particular parent and this particular grandParent.

 

But i cant get it to work. With an NAND operator, it would be rather easy, but there is no nand operator, and i cant do not and.

Any ideas?

[Hylke Bron]

Oh, if found the solution for this problem,

 

The following query makes the NAND effect:

 

child.find({
 $or:[
  {"id.grandParent": {$ne: "3"}},
  {"id.parent" : {$ne: "2"}},
  {"id.child" : {$ne: "0"}}
 ]
});

 

So what im doing here is finding all children that has at least one of the 3 statements true.

 

Each statement will return true when its not equal to resp. 3, 2 or 0. So the only document that will return false (and thus be excluded) in this or statement will be documents that have all of them equal to 3, 2 and 0.

 

I hope someone else finds this NAND operator useful

 

Hylke Bron