Date Extraction Operators
In MongoDB 3.4:
db.foursquare.aggregate( [
{ $project: {
_id: 0,
venue: '$venue.name',
*hour: { $hour: '$date' }*
} }
] );
{ "venue" : "London Paddington Railway Station (PAD)", "hour" : 8 }
{ "venue" : "Platform 7 (Heathrow Express)", "hour" : 8 }
{ "venue" : "Heathrow Express Train - Paddington [PAD] to Heathrow [HXX]", "hour" : 8 }
{ "venue" : "SkyTeam Lounge", "hour" : 9 }
{ "venue" : "Gate 15", "hour" : 10 }
{ "venue" : "Gate D23", "hour" : 13 }
{ "venue" : "Amsterdam Airport Schiphol (AMS)", "hour" : 13 }
{ "venue" : "Station Amsterdam Lelylaan", "hour" : 13 }
{ "venue" : "Station Amsterdam Sloterdijk", "hour" : 13 }
{ "venue" : "Station Amsterdam Centraal", "hour" : 13 }
{ "venue" : "Burgermeester", "hour" : 16 }
{ "venue" : "De Eland", "hour" : 17 }
...
In MongoDB 3.6:
db.foursquare.aggregate( [
{ $project: {
_id: 0,
venue: '$venue.name',
hour: { $hour: *{ date: '$date' }* }
} }
] );
In MongoDB 3.6:
db.foursquare.aggregate( [
{ $project: {
_id: 0,
venue: '$venue.name',
hour: { $hour: { date: '$date', *timezone: 'Europe/London'* } }
} }
] );
{ "venue" : "London Paddington Railway Station (PAD)", "hour" : 9 }
{ "venue" : "Platform 7 (Heathrow Express)", "hour" : 9 }
{ "venue" : "Heathrow Express Train - Paddington [PAD] to Heathrow [HXX]", "hour" : 9 }
{ "venue" : "SkyTeam Lounge", "hour" : 10 }
{ "venue" : "Gate 15", "hour" : 11 }
{ "venue" : "Gate D23", "hour" : 14 }
{ "venue" : "Amsterdam Airport Schiphol (AMS)", "hour" : 14 }
{ "venue" : "Station Amsterdam Lelylaan", "hour" : 14 }
{ "venue" : "Station Amsterdam Sloterdijk", "hour" : 14 }
{ "venue" : "Station Amsterdam Centraal", "hour" : 14 }
{ "venue" : "Burgermeester", "hour" : 17 }
{ "venue" : "De Eland", "hour" : 18 }
{ "venue" : "WEBclusive HQ", "hour" : 12 }
{ "venue" : "Station Utrecht Centraal", "hour" : 17 }
...