MongoDB Aggregate - Query to get most recent item in group
Given this source data:
"_id" : ObjectId("1"), "productID" : 1, "amount" : 1, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("2"), "productID" : 2, "amount" : 2, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("3"), "productID" : 3, "amount" : 3, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("6"), "productID" : 2, "amount" : 22, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
I want to get the most recent record for each product (keyed on productID
) and print out the full row for that record per product sorted on productID
. So my desired output from above would be:
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
I'm new to Mongo and having problems, managed to get most of it but couldn't delete the other older records for each product.
mongodb mongodb-query aggregation-framework
add a comment |
Given this source data:
"_id" : ObjectId("1"), "productID" : 1, "amount" : 1, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("2"), "productID" : 2, "amount" : 2, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("3"), "productID" : 3, "amount" : 3, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("6"), "productID" : 2, "amount" : 22, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
I want to get the most recent record for each product (keyed on productID
) and print out the full row for that record per product sorted on productID
. So my desired output from above would be:
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
I'm new to Mongo and having problems, managed to get most of it but couldn't delete the other older records for each product.
mongodb mongodb-query aggregation-framework
add a comment |
Given this source data:
"_id" : ObjectId("1"), "productID" : 1, "amount" : 1, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("2"), "productID" : 2, "amount" : 2, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("3"), "productID" : 3, "amount" : 3, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("6"), "productID" : 2, "amount" : 22, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
I want to get the most recent record for each product (keyed on productID
) and print out the full row for that record per product sorted on productID
. So my desired output from above would be:
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
I'm new to Mongo and having problems, managed to get most of it but couldn't delete the other older records for each product.
mongodb mongodb-query aggregation-framework
Given this source data:
"_id" : ObjectId("1"), "productID" : 1, "amount" : 1, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("2"), "productID" : 2, "amount" : 2, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("3"), "productID" : 3, "amount" : 3, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("6"), "productID" : 2, "amount" : 22, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
I want to get the most recent record for each product (keyed on productID
) and print out the full row for that record per product sorted on productID
. So my desired output from above would be:
"_id" : ObjectId("5"), "productID" : 1, "amount" : 11, "date" : ISODate("2017-02-02T00:00:00Z")
"_id" : ObjectId("7"), "productID" : 2, "amount" : 222, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("8"), "productID" : 3, "amount" : 33, "date" : ISODate("2017-02-03T00:00:00Z")
"_id" : ObjectId("4"), "productID" : 4, "amount" : 4, "date" : ISODate("2017-02-01T00:00:00Z")
I'm new to Mongo and having problems, managed to get most of it but couldn't delete the other older records for each product.
mongodb mongodb-query aggregation-framework
mongodb mongodb-query aggregation-framework
edited Feb 19 '17 at 10:36
sazzad
1,89461320
1,89461320
asked Feb 19 '17 at 9:23
sub123sub123
133
133
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You can use $last and $first operators. Note that you should sort documents before grouping:
db.so.aggregate([
$sort: productID:-1, date: -1 ,
$group:
_id : "$productID",
date: $last: "$date" ,
amount: $first: "$amount" ,
id : $first: "$_id"
,
$project: _id: "$id", productId: "$_id", date: 1, amount: 1
])
Output:
"_id" : 5,
"productId" : 1,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 11
,
"_id" : 7,
"productId" : 2,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 222
,
"_id" : 8,
"productId" : 3,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 33
,
"_id" : 4,
"productId" : 4,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 4
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
add a comment |
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can use $last and $first operators. Note that you should sort documents before grouping:
db.so.aggregate([
$sort: productID:-1, date: -1 ,
$group:
_id : "$productID",
date: $last: "$date" ,
amount: $first: "$amount" ,
id : $first: "$_id"
,
$project: _id: "$id", productId: "$_id", date: 1, amount: 1
])
Output:
"_id" : 5,
"productId" : 1,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 11
,
"_id" : 7,
"productId" : 2,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 222
,
"_id" : 8,
"productId" : 3,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 33
,
"_id" : 4,
"productId" : 4,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 4
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
add a comment |
You can use $last and $first operators. Note that you should sort documents before grouping:
db.so.aggregate([
$sort: productID:-1, date: -1 ,
$group:
_id : "$productID",
date: $last: "$date" ,
amount: $first: "$amount" ,
id : $first: "$_id"
,
$project: _id: "$id", productId: "$_id", date: 1, amount: 1
])
Output:
"_id" : 5,
"productId" : 1,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 11
,
"_id" : 7,
"productId" : 2,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 222
,
"_id" : 8,
"productId" : 3,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 33
,
"_id" : 4,
"productId" : 4,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 4
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
add a comment |
You can use $last and $first operators. Note that you should sort documents before grouping:
db.so.aggregate([
$sort: productID:-1, date: -1 ,
$group:
_id : "$productID",
date: $last: "$date" ,
amount: $first: "$amount" ,
id : $first: "$_id"
,
$project: _id: "$id", productId: "$_id", date: 1, amount: 1
])
Output:
"_id" : 5,
"productId" : 1,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 11
,
"_id" : 7,
"productId" : 2,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 222
,
"_id" : 8,
"productId" : 3,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 33
,
"_id" : 4,
"productId" : 4,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 4
You can use $last and $first operators. Note that you should sort documents before grouping:
db.so.aggregate([
$sort: productID:-1, date: -1 ,
$group:
_id : "$productID",
date: $last: "$date" ,
amount: $first: "$amount" ,
id : $first: "$_id"
,
$project: _id: "$id", productId: "$_id", date: 1, amount: 1
])
Output:
"_id" : 5,
"productId" : 1,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 11
,
"_id" : 7,
"productId" : 2,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 222
,
"_id" : 8,
"productId" : 3,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 33
,
"_id" : 4,
"productId" : 4,
"date" : ISODate("2017-02-01T00:00:00.000Z"),
"amount" : 4
edited Feb 19 '17 at 9:42
answered Feb 19 '17 at 9:36
Sergey BerezovskiySergey Berezovskiy
187k23315364
187k23315364
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
add a comment |
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
Thanks that's a big help. One thing though - I am not aware of the full document schema in advance (ie this is generic)- so I know I will have a fixed date field and a id field (date, productID) but there will be many other fields that are undefined at runtime - how could I return all the fields from an object without specifying them.
– sub123
Feb 19 '17 at 21:03
add a comment |
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