77 lines
2.5 KiB
Markdown
77 lines
2.5 KiB
Markdown
---
|
||
id: 587d7fb9367417b2b2512c12
|
||
title: 通过链式调用辅助查询函数来缩小搜索结果
|
||
challengeType: 2
|
||
forumTopicId: 301533
|
||
dashedName: chain-search-query-helpers-to-narrow-search-results
|
||
---
|
||
|
||
# --description--
|
||
|
||
如果不给 `Model.find()`（或者别的搜索方法）的最后一个参数传入回调函数, 查询将不会执行。 可以将查询条件存储在变量中供以后使用， 也可以通过链式调用这类变量来构建新的查询字段。 实际的数据库操作会在最后调用 `.exec()` 方法时执行。 必须把回调函数传给最后一个方法。 Mongoose 提供了许多辅助查询函数, 这里使用最常见的一种。
|
||
|
||
# --instructions--
|
||
|
||
修改 `queryChain` 函数来查询喜欢 `foodToSearch` 食物的人。 同时，需要将查询结果按 `name` 属性排序， 查询结果应限制在两个 document 内，并隐藏 age 属性。 请链式调用 `.find()`、`.sort()`、`.limit()` 和 `.select()`，并在最后调用 `.exec()`， 并将 `done(err, data)` 回调函数传入 `exec()`。
|
||
|
||
# --hints--
|
||
|
||
应该成功地链式调用辅助查询函数。
|
||
|
||
```js
|
||
(getUserInput) =>
|
||
$.ajax({
|
||
url: getUserInput('url') + '/_api/query-tools',
|
||
type: 'POST',
|
||
contentType: 'application/json',
|
||
data: JSON.stringify([
|
||
{ name: 'Pablo', age: 26, favoriteFoods: ['burrito', 'hot-dog'] },
|
||
{ name: 'Bob', age: 23, favoriteFoods: ['pizza', 'nachos'] },
|
||
{ name: 'Ashley', age: 32, favoriteFoods: ['steak', 'burrito'] },
|
||
{ name: 'Mario', age: 51, favoriteFoods: ['burrito', 'prosciutto'] }
|
||
])
|
||
}).then(
|
||
(data) => {
|
||
assert.isArray(data, 'the response should be an Array');
|
||
assert.equal(
|
||
data.length,
|
||
2,
|
||
'the data array length is not what expected'
|
||
);
|
||
assert.notProperty(
|
||
data[0],
|
||
'age',
|
||
'The returned first item has too many properties'
|
||
);
|
||
assert.equal(
|
||
data[0].name,
|
||
'Ashley',
|
||
'The returned first item name is not what expected'
|
||
);
|
||
assert.notProperty(
|
||
data[1],
|
||
'age',
|
||
'The returned second item has too many properties'
|
||
);
|
||
assert.equal(
|
||
data[1].name,
|
||
'Mario',
|
||
'The returned second item name is not what expected'
|
||
);
|
||
},
|
||
(xhr) => {
|
||
throw new Error(xhr.responseText);
|
||
}
|
||
);
|
||
```
|
||
|
||
# --solutions--
|
||
|
||
```js
|
||
/**
|
||
Backend challenges don't need solutions,
|
||
because they would need to be tested against a full working project.
|
||
Please check our contributing guidelines to learn more.
|
||
*/
|
||
```
|