MongoDB $type operator
Description
In this chapter, we will continue to discuss the conditional operator $type in MongoDB.
The $type operator is based on the BSON type to retrieve matching data types in the collection and returns the result.
The types that can be used in MongoDB are shown in the following table:
Type | Number | Remarks |
---|---|---|
Double | 1 | |
String | 2 | |
Object | 3 | |
Array | 4 | |
Binary data | 5 | |
Undefined | 6 | is obsolete. |
Object id | 7 | |
Boolean | 8 | |
Date | 9 | |
Null | 10 | |
Regular Expression | 11 | |
JavaScript | 13 | |
Symbol | 14 | |
JavaScript (with scope ) | 15 | |
32-bit integer | 16 | |
Timestamp | 17 | |
64-bit integer | 18 | |
Min key | 255 | Query with -1. |
Max key | 127 |
The database name we use is "php" Our collection name is "col", and the following is the data we inserted.
Simple collection "col":
>db.col.insert({ title: 'PHP 教程', description: 'PHP 是一种创建动态交互性站点的强有力的服务器端脚本语言。', by: 'php中文网', url: 'http://www.php.cn', tags: ['php'], likes: 200 })
>db.col.insert({title: 'Java 教程', description: 'Java 是由Sun Microsystems公司于1995年5月推出的高级程序设计语言。', by: 'php中文网', url: 'http://www.php.cn', tags: ['java'], likes: 150 })
>db.col.insert({title: 'MongoDB 教程', description: 'MongoDB 是一个 Nosql 数据库', by: 'php中文网', url: 'http://www.php.cn', tags: ['mongodb'], likes: 100 })
Use the find() command to view data:
> db.col.find() { "_id" : ObjectId("56066542ade2f21f36b0313a"), "title" : "PHP 教程", "description" : "PHP 是一种创建动态交互性站点的强有力的服务器端脚本语言。", "by" : "php中文网", "url" : "http://www.php.cn", "tags" : [ "php" ], "likes" : 200 } { "_id" : ObjectId("56066549ade2f21f36b0313b"), "title" : "Java 教程", "description" : "Java 是由Sun Microsystems公司于1995年5月推出的高级程序设计语言。", "by" : "php中文网", "url" : "http://www.php.cn", "tags" : [ "java" ], "likes" : 150 } { "_id" : ObjectId("5606654fade2f21f36b0313c"), "title" : "MongoDB 教程", "description" : "MongoDB 是一个 Nosql 数据库", "by" : "php中文网", "url" : "http://www.php.cn", "tags" : [ "mongodb" ], "likes" : 100 }
MongoDB Operator - $type Example
If you want to get the data whose title is String in the "col" collection, you can use the following command:
db.col.find({"title" : {$type : 2}})
The output result is:
{ "_id" : ObjectId("56066542ade2f21f36b0313a"), "title" : "PHP 教程", "description" : "PHP 是一种创建动态交互性站点的强有力的服务器端脚本语言。", "by" : "php中文网", "url" : "http://www.php.cn", "tags" : [ "php" ], "likes" : 200 } { "_id" : ObjectId("56066549ade2f21f36b0313b"), "title" : "Java 教程", "description" : "Java 是由Sun Microsystems公司于1995年5月推出的高级程序设计语言。", "by" : "php中文网", "url" : "http://www.php.cn", "tags" : [ "java" ], "likes" : 150 } { "_id" : ObjectId("5606654fade2f21f36b0313c"), "title" : "MongoDB 教程", "description" : "MongoDB 是一个 Nosql 数据库", "by" : "php中文网", "url" : "http://www.php.cn", "tags" : [ "mongodb" ], "likes" : 100 }