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Type:
New Feature
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Resolution: Duplicate
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: Aggregation Framework
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Labels:None
another way to implement cross-collections joins.
ex: 2 collections: Books and Authors.
book = { _id:1, title: 'A', author_id: 1 }
author = { _id: 1, name: 'Me' }
db.aggregate(
{$collection: 'book', $match: ...},
{$collection: 'author', $match: ...},
...
{$group: ...},
{$project: ...}
)
in result (example too):
books_with_authors = [
{_id:1, title: 'A', author: { _id: 1, name: 'Me' }},
...
]
- duplicates
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- Closed
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