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03_updating_documents.md

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Use the sample_training database as your database in the following commands.

use sample_training

Find all documents in the zips collection where the zip field is equal to "12434".

db.zips.find({ "zip": "12534" }).pretty()

Find all documents in the zips collection where the city field is equal to "HUDSON".

db.zips.find({ "city": "HUDSON" }).pretty()

Find how many documents in the zips collection have the city field equal to "HUDSON".

db.zips.find({ "city": "HUDSON" }).count()

Update all documents in the zips collection where the city field is equal to "HUDSON" by adding 10 to the current value of the "pop" field.

db.zips.updateMany({ "city": "HUDSON" }, { "$inc": { "pop": 10 } })

Update a single document in the zips collection where the zip field is equal to "12534" by setting the value of the "pop" field to 17630.

db.zips.updateOne({ "zip": "12534" }, { "$set": { "pop": 17630 } })

Update a single document in the zips collection where the zip field is equal to "12534" by setting the value of the "popupation" field to 17630.

db.zips.updateOne({ "zip": "12534" }, { "$set": { "population": 17630 } })

Find all documents in the grades collection where the student_id field is 151 , and the class_id field is 339.

db.grades.find({ "student_id": 151, "class_id": 339 }).pretty()

Find all documents in the grades collection where the student_id field is 250 , and the class_id field is 339.

db.grades.find({ "student_id": 250, "class_id": 339 }).pretty()

Update one document in the grades collection where the student_id is 250 *, and the class_id field is 339 , by adding a document element to the "scores" array.

db.grades.updateOne({ "student_id": 250, "class_id": 339 },
                    { "$push": { "scores": { "type": "extra credit",
                                             "score": 100 }
                                }
                     })