Force mongodb to output strict JSON

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Top 5 Answer for Force mongodb to output strict JSON

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97

The MongoDB shell speaks Javascript, so the answer is simple: use JSON.stringify(). If your command is db.serverStatus(), then you can simply do this:

JSON.stringify(db.serverStatus()) 

This won't output the proper "strict mode" representation of each of the fields ({ "floatApprox": <number> } instead of { "$numberLong": "<number>" }), but if what you care about is getting standards-compliant JSON out, this'll do the trick.

vote vote

85

I have not found a way to do this in the mongo shell, but as a workaround, mongoexport can run queries and its output uses strict mode and can be piped into other commands that expect JSON input (such as json_pp or jq). For example, suppose you have the following mongo shell command to run a query, and you want to create a pipeline using that data:

db.myItemsCollection.find({creationDate: {$gte: ISODate("2016-09-29")}}).pretty() 

Convert that mongo shell command into this shell command, piping for the sake of example to `json_pp:

mongoexport --jsonArray -d myDbName -c myItemsCollection -q '{"creationDate": {"$gte": {"$date": "2016-09-29T00:00Z"}}}' | json_pp 

You will need to convert the query into strict mode format, and pass the database name and collection name as arguments, as well as quote properly for your shell, as shown here.

vote vote

78

In case of findOne

JSON.stringify(db.Bill.findOne({'a': '123'})) 

In case of a cursor

db.Bill.find({'a': '123'}).forEach(r=>print(JSON.stringify(r))) 

or

print('[') + db.Bill.find().limit(2).forEach(r=>print(JSON.stringify(r) + ',')) + print(']') 

will output

[{a:123},{a:234},] 

the last one will have a ',' after the last item...remove it

vote vote

66

To build on the answer from @jbyler, you can strip out the numberLongs using sed after you get your data - that is if you're using linux.

mongoexport --jsonArray -d dbName -c collection -q '{fieldName: {$regex: ".*turkey.*"}}' | sed -r 's/\{ "[$]numberLong" : "([0-9]+)" }/"\1"/g' | json_pp 
vote vote

55

EDIT: This will transform a given document, but will not work on a list of documents. Changed find to findOne.

Adding

.forEach(function(results){results._id=results._id.toString();printjson(results)})` 

to a findOne() will output valid JSON.

Example:

db   .users   .findOne()   .forEach(function (results) {     results._id = results._id.toString();     printjson(results)   }) 

Source: https://www.mydbaworld.com/mongodb-shell-output-valid-json/

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