发布于 2015-09-14 14:54:06 | 165 次阅读 | 评论: 0 | 来源: 网络整理
This document contains a list of all operators used with MongoDB in version 2.2.3. See 核心操作（CRUD） for a higher level overview of the operations that use these operators, and 查询, 更新, 投射, 和集合算符 for a more condensed index of these operators.
注解
To express equal to (e.g. =) in the MongoDB query language, use JSON { key:value } structure. Consider the following prototype:
db.collection.find( { field: value } )
For example:
db.collection.find( { a: 42 } )
This query selects all the documents the where the a field holds a value of 42.
You may combine comparison operators to specify ranges:
db.collection.find( { field: { $gt: value1, $lt: value2 } } );
This statement returns all documents with field between value1 and value2.
注解
Fields containing arrays match conditional operators, if only one item matches. Therefore, the following query:
db.collection.find( { field: { $gt:0, $lt:2 } } );
Will match a document that contains the following field:
{ field: [-1,3] }