How does MongoDB handle relationships between documents

Question

Can you tell me How does MongoDB handle relationships between documents?

Answer 1

MongoDB, being a NoSQL database, does not enforce traditional relational constraints like a relational database (e.g., foreign keys in SQL). Instead, it handles relationships between documents using embedding and referencing. The choice between these approaches depends on data structure, access patterns, and scalability needs.

1. Embedding (Denormalization)

Related data is stored within the same document as nested fields or arrays.

Example: A blog post with comments:

{

  _id: ObjectId("post1"),

  title: "MongoDB Relationships",

  content: "Understanding relationships in MongoDB",

  comments: [

    { user: "Alice", text: "Great post!" },

    { user: "Bob", text: "Very helpful!" }

  ]

}