67 lines
1.6 KiB
Markdown
67 lines
1.6 KiB
Markdown
---
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title: Chain Search Query Helpers to Narrow Search Results
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localeTitle: 链搜索查询帮助缩小搜索结果
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---
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## 链搜索查询帮助缩小搜索结果
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1. 创建但不执行查找查询
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```javascript
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Model.find( {name: 'Leah'} )
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```
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2. 将查询查询存储到变量中以供以后使用：
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```javascript
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var findQuery = YourModel.find( {name: 'Leah'} )
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```
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3. 要对数组进行排序：
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```javascript
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yourArray.sort( {age: 1} ) // Here: 1 for ascending order and -1 for descending order.
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```
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4. 要限制数组的大小：
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```javascript
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yourArray.limit(5) // return array which has 5 items in it.
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```
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5. 要从结果中隐藏某些属性：
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```javascript
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yourArray.select( {name: 0, age: 1} ) // Here: 0 means false and thus hide name property; 1 means true so age property will show.
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```
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6. 要执行此查询，您可以：
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1）回调：
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```javascript
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YourQuery.exec(function(err, docs) {
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//do something here
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})
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```
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或者2）承诺
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```javascript
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YourQuery.exec.then(function(err, docs) {
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//do something here
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})
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```
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7. 将它们连在一起：
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```javascript
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Person.find({age: 55}).sort({name: -1}).limit(5).select( {favoriteFoods: 0} ).exec(function(error, people) {
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//do something here
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})
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```
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这是一个存根。 [帮助我们的社区扩展它](https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/mongodb-and-mongoose/chain-search-query-helpers-to-narrow-search-results/index.md) 。
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[这种快速风格指南有助于确保您的拉取请求被接受](https://github.com/freecodecamp/guides/blob/master/README.md) 。 |