Element Query Operators元素查询运算符
Element operators return data based on field existence or data types.元素运算符根据字段的存在或数据类型返回数据。
Note
For details on a specific operator, including syntax and examples, click on the link to the operator's reference page.有关特定运算符的详细信息,包括语法和示例,请单击该运算符参考页的链接。
$exists | |
$type |