MaxInterview - mongodb add or update document fields only if they don 27t exist

showing results for - "mongodb add or update document fields only if they don 27t exist"

1db.foo.update({'field': {$exists : false}}, {$set: {'field': ''}})
2// for multiple update do this
3db.foo.update({'field': {$exists : false}}, {$set: {'field': ''}}, false, true)

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