在MongoDB中根据字段的数量类型来查询数据使用$type操作符来实现，具体使用法语：
|
1
|
db.集合名.
find
({$
type
:类型值})
//
这里的类型值能使用Number也能使用
alias
|
举个例子：
|
1
2
|
db.person.
find
({address:{$
type
:2}})
//
查询address字段数据类型为字符串
db.person.
find
({address:{$
type
:
"string"
}})
//
查询address字段数据类型为字符串
|
$type 有效的类型值，如下：
| Type | Number | Alias | Notes |
|---|---|---|---|
| Double | 1 | “double” | |
| String | 2 | “string” | |
| Object | 3 | “object” | |
| Array | 4 | “array” | |
| Binary data | 5 | “binData” | |
| Undefined | 6 | “undefined” | Deprecated. |
| ObjectId | 7 | “objectId” | |
| Boolean | 8 | “bool” | |
| Date | 9 | “date” | |
| Null | 10 | “null” | |
| Regular Expression | 11 | “regex” | |
| DBPointer | 12 | “dbPointer” | Deprecated. |
| JavaScript | 13 | “javascript” | |
| Symbol | 14 | “symbol” | Deprecated. |
| JavaScript (with scope) | 15 | “javascriptWithScope” | |
| 32-bit integer | 16 | “int” | |
| Timestamp | 17 | “timestamp” | |
| 64-bit integer | 18 | “long” | |
| Decimal128 | 19 | “decimal” | New in version 3.4. |
| Min key | -1 | “minKey” | |
| Max key | 127 | “maxKey” |
官网参考：https://docs.mongodb.com/manual/reference/operator/query/type/index.html
原文转自: http://www.xuexiyuan.cn/article/detail/107.html