you have too many braces,
here’s correct command:
db.settlements.update(
{
'StoreID': "51ea54279d867b040b000008",
'Date': ISODate("2013-06-28T18:30:00Z")
},
{
$unset: {
'NID' : "",
'PID' : ""
},
$set: {
'SettStatus': 'start',
'Status': 'pending'
}
}
);
in your command, you’re using $set as <options>
in update command, not as part of <update>
http://docs.mongodb.org/manual/core/update/#crud-update-update