MongoDB's Find usage

1. Returns the specified key value: Db.list.find ({condition},{name: "Any value", Age: Any value}); The result will only return the _ID name age three key values, if you do not want to _id you need to write _id:0 explicitly to the second set of key values;

2. Specify the range of values for the key to return the specified key value: Db.list.find ({age:{$gte: 4, $lte: 25}},{name: "Any value", Age: Any value, _id:0}); Results filter out key values that are older than 4 or less than 25 and contain only name age;

3. A value of the shaving key returns the specified key value: Db.list.find ({age:{$ne: 14},{name: "1", age:2,_id:0}), and the result filters out the record with age 14 and the key value and contains only name ages;

MongoDB's Find usage