Life Lei dog MongoDB----MONGODB---3---comparison operator

$lt < less than

$lte <= less than and equal smaller than or equal to

$GT > greater than greater than

$gte >= greanter than and equal greater than or equal to

$ne! = Not equal range

The simple usage is as follows:

Demand:

Users less than 30 are queried:

Db. user. Find ({age:{$lt:}},{_id:0});

Requirements: 18-25-year-old users are queried

Db. user. Find ({age:{$gte:$lte:)});

Note: Here is a feature that is for the age of the key to query, can be in the object of the comparison operator, write multiple, it is to meet the conditions therein.

Demand:

Find a 18-25-year-old male and user

Db. user. Find ({$and:[{sex: ' Male '},{age:{$gte: $lte:]}]},{_id:0 });

Demand:

Check with 18 or 25-year-old users

Db. user. Find ({$or:[age:18],[age:22] },{_id:0});

Here we have a feature, that is, for age to compare, if this is the case, we can also use $in to achieve the same effect

Db. user. Find ({age:{$in:[18,22]}},{_id:0});

Search for a person who is gender-or between 18-25 years of age:

Db. user. Find ({$or:[{sex: ' Male '},{age:{$gte: $lte:]}]},{_id:0 })

Non-operation, which is our common inversion:

Querying users who are not 18-22

Db. user. Find ({age:{$not: {$gte:$lte:}}},{_id:0})

Life Lei dog MongoDB----MONGODB---3---comparison operator