Array Query Operators数组查询运算符
Array operators return data based on array conditions.数组运算符根据数组条件返回数据。
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。
$all | |
$elemMatch | $elemMatch conditions.$elemMatch 条件匹配,则选择文档。 |
$size |
For examples on querying array fields, see:有关查询数组字段的示例,请参阅: