Database Manual / Reference / Query Language / Query Predicates / Comparison

$gte (expression operator)（表达式运算符）

Definition定义

$gte

$gte selects the documents where the value of the specified field is greater than or equal to (i.e. >=) a specified value (e.g. value.)选择指定字段的值大于或等于（即>=）指定值（例如value）的文档

For most data types, comparison operators only perform comparisons on fields where the BSON type matches the query value's type. MongoDB supports limited cross-BSON comparison through Type Bracketing.对于大多数数据类型，比较运算符仅对BSON类型与查询值类型匹配的字段执行比较。MongoDB支持通过类型花括号进行有限的跨BSON比较。

Compatibility兼容性

You can use $gte for deployments hosted in the following environments:您可以将$gte用于在以下环境中托管的部署：

  • MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud：云中MongoDB部署的完全托管服务
  • MongoDB Enterprise: The subscription-based, self-managed version of MongoDB：MongoDB的基于订阅的自我管理版本
  • MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB：MongoDB的源代码可用、免费使用和自我管理版本

Syntax语法

The $gte operator has the following form:$gte运算符具有以下形式：

{ field: { $gte: value } }

Examples示例

The following examples use the inventory collection. Create the collection:以下示例使用inventory集合。创建集合：

db.inventory.insertMany( [
   {
      item: "nuts", quantity: 30,
      carrier: { name: "Shipit", fee: 3 }
   },
   {
      item: "bolts", quantity: 50,
      carrier: { name: "Shipit", fee: 4 }
   },
   {
      item: "washers", quantity: 10,
      carrier: { name: "Shipit", fee: 1 }
   }
] )

Match Document Fields匹配文档字段

Select all documents in the inventory collection where quantity is greater than or equal to 20:选择inventory领用中quantity大于等于20的所有单据：

db.inventory.find( { quantity: { $gte: 20 } } )

Example output:输出示例：

 {
   _id: ObjectId("61bb51211b83c864e3bbe037"),
   item: 'nuts',
   quantity: 30,
   carrier: { name: 'Shipit', fee: 3 }
 },
 {
   _id: ObjectId("61bb51211b83c864e3bbe038"),
   item: 'bolts',
   quantity: 50,
   carrier: { name: 'Shipit', fee: 4 }
}

Perform an Update Based on Embedded Document Fields基于嵌入式文档字段执行更新

The following example sets the price field based on a $gte comparison against a field in an embedded document.以下示例基于$gte与嵌入式文档中的字段的比较来设置price字段。

db.inventory.updateMany(
   { "carrier.fee": { $gte: 2 } }, { $set: { "price": 9.99 } }
)

Example output:输出示例：

{
  _id: ObjectId("61bb51211b83c864e3bbe037"),
  item: 'nuts',
  quantity: 30,
  carrier: { name: 'Shipit', fee: 3 },
  price: 9.99
},
{
  _id: ObjectId("61bb51211b83c864e3bbe038"),
  item: 'bolts',
  quantity: 50,
  carrier: { name: 'Shipit', fee: 4 },
  price: 9.99
}

This updateMany() operation searches for an embedded document, carrier, with a subfield named fee. 这个updateMany()操作搜索一个嵌入式文档carrier，其中包含一个名为fee的子字段。It sets { price: 9.99 } in each document where fee has a value greater than or equal to 2.它在每个fee（费用）值大于或等于2的文档中设置{ price: 9.99 }。

To set the value of the price field in only the first document where carrier.fee is greater than 2, use updateMany().要仅在carrier.fee大于2的第一个文档中设置price字段的值，请使用updateMany()。

Tip