How to remove a field from a document

Question

The database schema:

{
    _id: "kun2",
    result150160: [10,20,30];
    moon: 4
}

I want to delete the whole field result150160 by the client with a variable:

var deleteresult = "result150160"
Box.update( {_id: this._id} , {$unset: { deleteresult } } );

Answer 1

Try this it should work for you:

var deleteresult = "result150160";    
var updateQuery={$unset:{}};   
updateQuery.$unset[deleteresult]=1;   
Box.update( {_id: this._id} ,updateQuery,false,true);

Answer 2

The correct syntax is this:

Box.update( {_id: this._id} , {$unset: { deleteresult : "" } } );

You have to specify a value for the $unset operation : { deleteresult : "" }. Even if it is empty.

Checkout the relevant docs:

db.collection.update( { field: value1 }, { $unset: { field1: "" } } );
The above example deletes field1 in collection from documents where field has a value of value1. The value of the field in the $unset statement (i.e. "" above) does not impact the operation.

Answer 3

You could do:

var deleteresult = {};
deleteresult["result150160"] = true
Box.update( {_id: this._id} , {$unset: deleteresult } );

Basically you have to use a key value pair, it doesn't matter what you use for true, as long as theres something there.