Performing Queries: Query Modifications -- Part 1

• How can you limit the fields returned?

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  • Use projections
  • find({query},{field1:1,field2:0})
  • 1 = include, 0 = exclude

• How do you limit the number of documents returned?

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  • db.collection.find().limit()

• How do you find one document?

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  • db.collection.findOne()
  • db.collection.find().limit(1)

• How do you find a document where the value is in an array?

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  • db.world_gdp.find({"field.element":{value}})