What is a nested document (embedded document)?
An embedded document is a document stored as a field inside another document. It lets you describe related data within a single structure instead of spreading it across separate entities.
Example:
json
{
"name": "Alex",
"address": {
"city": "Berlin",
"street": "Main St.",
"house": 12
}
}Key characteristics
- Stored inside the main document There's no separate collection or record, everything lives in one object.
- Convenient for related data It fits "one-to-one" entities or "anything that logically belongs to the object".
- Cuts down the number of queries No JOIN is needed, the data is read straight from one document.
Summary: an embedded document is a way to store related data entirely inside one MongoDB document, preserving structure and simplifying access.
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