Lookups in MongoDB
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I have multiple lookups in pipeline mongo query. if any populate field is undefined I don't want to omit this row. can I do this?
const pipeline = [
$unwind: "$wholesaler" ,
$lookup:
from: "serviceproviders",
localField: "serviceProvider",
foreignField: "_id",
as: "serviceProvider"
,
$unwind: "$serviceProvider" ,
$sort:
createdAt: 1,
updatedAt: 1
];
If service provider id is not found its return rest of the object that what I want.
mongodb aggregation-framework lookup
add a comment |
I have multiple lookups in pipeline mongo query. if any populate field is undefined I don't want to omit this row. can I do this?
const pipeline = [
$unwind: "$wholesaler" ,
$lookup:
from: "serviceproviders",
localField: "serviceProvider",
foreignField: "_id",
as: "serviceProvider"
,
$unwind: "$serviceProvider" ,
$sort:
createdAt: 1,
updatedAt: 1
];
If service provider id is not found its return rest of the object that what I want.
mongodb aggregation-framework lookup
Can you please provide a sample document?
– rodrigoap
Nov 15 '18 at 14:29
add a comment |
I have multiple lookups in pipeline mongo query. if any populate field is undefined I don't want to omit this row. can I do this?
const pipeline = [
$unwind: "$wholesaler" ,
$lookup:
from: "serviceproviders",
localField: "serviceProvider",
foreignField: "_id",
as: "serviceProvider"
,
$unwind: "$serviceProvider" ,
$sort:
createdAt: 1,
updatedAt: 1
];
If service provider id is not found its return rest of the object that what I want.
mongodb aggregation-framework lookup
I have multiple lookups in pipeline mongo query. if any populate field is undefined I don't want to omit this row. can I do this?
const pipeline = [
$unwind: "$wholesaler" ,
$lookup:
from: "serviceproviders",
localField: "serviceProvider",
foreignField: "_id",
as: "serviceProvider"
,
$unwind: "$serviceProvider" ,
$sort:
createdAt: 1,
updatedAt: 1
];
If service provider id is not found its return rest of the object that what I want.
mongodb aggregation-framework lookup
mongodb aggregation-framework lookup
edited Nov 15 '18 at 16:16
Hardik Shah
1,7422824
1,7422824
asked Nov 15 '18 at 14:25
user8590996
Can you please provide a sample document?
– rodrigoap
Nov 15 '18 at 14:29
add a comment |
Can you please provide a sample document?
– rodrigoap
Nov 15 '18 at 14:29
Can you please provide a sample document?
– rodrigoap
Nov 15 '18 at 14:29
Can you please provide a sample document?
– rodrigoap
Nov 15 '18 at 14:29
add a comment |
1 Answer
1
active
oldest
votes
From MongoDB document:
preserveNullAndEmptyArrays
If true, if the path is
null, missing, or an empty array, $unwind outputs the document. If
false, $unwind does not output a document if the path is null,
missing, or an empty array.
The default value is false.
So use below:
$unwind:
path: "$serviceProvider",
"preserveNullAndEmptyArrays": true
Check here with sample data (https://mongoplayground.net/p/aljWODXfwQg)
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
From MongoDB document:
preserveNullAndEmptyArrays
If true, if the path is
null, missing, or an empty array, $unwind outputs the document. If
false, $unwind does not output a document if the path is null,
missing, or an empty array.
The default value is false.
So use below:
$unwind:
path: "$serviceProvider",
"preserveNullAndEmptyArrays": true
Check here with sample data (https://mongoplayground.net/p/aljWODXfwQg)
add a comment |
From MongoDB document:
preserveNullAndEmptyArrays
If true, if the path is
null, missing, or an empty array, $unwind outputs the document. If
false, $unwind does not output a document if the path is null,
missing, or an empty array.
The default value is false.
So use below:
$unwind:
path: "$serviceProvider",
"preserveNullAndEmptyArrays": true
Check here with sample data (https://mongoplayground.net/p/aljWODXfwQg)
add a comment |
From MongoDB document:
preserveNullAndEmptyArrays
If true, if the path is
null, missing, or an empty array, $unwind outputs the document. If
false, $unwind does not output a document if the path is null,
missing, or an empty array.
The default value is false.
So use below:
$unwind:
path: "$serviceProvider",
"preserveNullAndEmptyArrays": true
Check here with sample data (https://mongoplayground.net/p/aljWODXfwQg)
From MongoDB document:
preserveNullAndEmptyArrays
If true, if the path is
null, missing, or an empty array, $unwind outputs the document. If
false, $unwind does not output a document if the path is null,
missing, or an empty array.
The default value is false.
So use below:
$unwind:
path: "$serviceProvider",
"preserveNullAndEmptyArrays": true
Check here with sample data (https://mongoplayground.net/p/aljWODXfwQg)
edited Nov 15 '18 at 14:47
answered Nov 15 '18 at 14:40
Hardik ShahHardik Shah
1,7422824
1,7422824
add a comment |
add a comment |
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Can you please provide a sample document?
– rodrigoap
Nov 15 '18 at 14:29