Use the $set operator to do that: db.foo.update({bar: 100}, {$set: {bar: 1000}}, false, true). The fourth parameter sets the multi option to true so that ... ... <看更多>

MongoDB hello: Shows how to update a field with the value of another field by using either eval (nolock, for mongodb >= 1.8) or map/reduce (mongodb 1.6). ... <看更多>

MongoCollection::update — Update records based on a given criteria ... Note: If this option is used and journaling is disabled, MongoDB 2.6+ will raise an ... ... <看更多>

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