» Node.js:使用Express构建REST API » 2. 开发 » 2.11 搜索

搜索

在 RESTful API 中实现搜索功能,你需要先定义一个处理搜索参数的路由,然后在底层数据库中使用前缀或全文索引进行搜索,再返回搜索结果。

在 MySQL 中搜索

添加 keyword 参数到 BookManager.getBooksdomain/gateway/book_manager.ts

@@ -5,5 +5,5 @@ export interface BookManager {
   updateBook(id: number, b: Book): Promise<void>;
   deleteBook(id: number): Promise<void>;
   getBook(id: number): Promise<Book | null>;
-  getBooks(offset: number): Promise<Book[]>;
+  getBooks(offset: number, keyword: string): Promise<Book[]>;
 }

添加搜索功能,infrastructure/database/mysql.ts

@@ -69,10 +69,18 @@ export class MySQLPersistence implements BookManager {
     return rows.length ? (rows[0] as Book) : null;
   }
 
-  async getBooks(offset: number): Promise<Book[]> {
-    const [rows] = await this.db
-      .promise()
-      .query("SELECT * FROM books LIMIT ?, ?", [offset, this.page_size]);
+  async getBooks(offset: number, keyword: string): Promise<Book[]> {
+    let query = "SELECT * FROM books";
+    let params: (string | number)[] = [];
+
+    if (keyword) {
+      query += " WHERE title LIKE ? OR author LIKE ?";
+      params = [`%${keyword}%`, `%${keyword}%`];
+    }
+
+    query += " LIMIT ?, ?";
+    params.push(offset, this.page_size);
+    const [rows] = await this.db.promise().query(query, params);
     return rows as Book[];
   }

注意

在生产数据库中不要使用 LIKE %keyword%。与其他搜索方法相比,这种方法效率较低,特别是在处理大型数据集时。 LIKE %keyword% 语法强制数据库执行全表扫描或索引扫描,这可能会很慢,特别是在大型表上。它不能有效地利用索引,导致查询性能较慢。
如果你的用例允许,考虑使用前缀搜索(例如,LIKE keyword%)。与子字符串搜索相比,这可以更有效地利用索引。

调整 application/executor/book_operator.ts

@@ -23,13 +23,18 @@ export class BookOperator {
     return await this.bookManager.getBook(id);
   }
 
-  async getBooks(offset: number): Promise<Book[]> {
+  async getBooks(offset: number, query: string): Promise<Book[]> {
+    // Search results, don't cache it
+    if (query) {
+      return await this.bookManager.getBooks(offset, query);
+    }
+    // Normal list of results
     const k = `${booksKey}-${offset}`;
     const cache_value = await this.cacheHelper.load(k);
     if (cache_value) {
       return JSON.parse(cache_value);
     }
-    const books = await this.bookManager.getBooks(offset);
+    const books = await this.bookManager.getBooks(offset, "");
     await this.cacheHelper.save(k, JSON.stringify(books));
     return books;
   }

传入 query 参数,adapter/router.ts

@@ -21,7 +21,10 @@ class RestHandler {
       offset = 0;
     }
     try {
-      const books = await this.bookOperator.getBooks(offset);
+      const books = await this.bookOperator.getBooks(
+        offset,
+        req.query.q as string
+      );
       res.status(200).json(books);
     } catch (err) {
       console.error(`Failed to get books: ${err}`);

保存修改,重启 api 服务器。

使用 curl 搜索图书

搜索图书

curl -X GET "http://localhost:3000/books?q=and"

结果:

[
  {
    "id": 7,
    "title": "Pride and Prejudice",
    "author": "Jane Austen",
    "published_at": "1813-01-28",
    "description": "A classic novel exploring the themes of love, reputation, and social class in Georgian England.",
    "isbn": "9780486284736",
    "total_pages": 279,
    "created_at": "2024-03-01T21:48:25.000Z",
    "updated_at": "2024-03-01T21:48:25.000Z"
  },
  {
    "id": 13,
    "title": "War and Peace",
    "author": "Leo Tolstoy",
    "published_at": "1869-01-01",
    "description": "A novel depicting the Napoleonic era in Russia, exploring themes of love, war, and historical determinism.",
    "isbn": "9781400079988",
    "total_pages": 1392,
    "created_at": "2024-03-01T21:48:25.000Z",
    "updated_at": "2024-03-01T21:48:25.000Z"
  },
  {
    "id": 14,
    "title": "Alice’s Adventures in Wonderland",
    "author": "Lewis Carroll",
    "published_at": "1865-11-26",
    "description": "A children’s novel featuring a young girl named Alice who falls into a fantastical world populated by peculiar creatures.",
    "isbn": "9780141439761",
    "total_pages": 192,
    "created_at": "2024-03-01T21:48:25.000Z",
    "updated_at": "2024-03-01T21:48:25.000Z"
  }
]

搜索图书并带一个偏移

curl -X GET "http://localhost:3000/books?q=the&o=4"

结果:

[
  {
    "id": 12,
    "title": "The Adventures of Huckleberry Finn",
    "author": "Mark Twain",
    "published_at": "1884-12-10",
    "description": "A novel depicting the journey of a young boy and an escaped slave along the Mississippi River.",
    "isbn": "9780486280615",
    "total_pages": 366,
    "created_at": "2024-03-01T21:48:25.000Z",
    "updated_at": "2024-03-01T21:48:25.000Z"
  },
  {
    "id": 15,
    "title": "The Odyssey",
    "author": "Homer",
    "published_at": "8th Century BC",
    "description": "An ancient Greek epic poem attributed to Homer, detailing the journey of Odysseus after the Trojan War.",
    "isbn": "9780140268867",
    "total_pages": 541,
    "created_at": "2024-03-01T21:48:25.000Z",
    "updated_at": "2024-03-01T21:48:25.000Z"
  }
]

在 mongoDB 中搜索

添加 keyword 参数到 ReviewManager.getReviewsOfBookdomain/gateway/review_manager.ts

@@ -5,5 +5,5 @@ export interface ReviewManager {
   updateReview(id: string, r: Review): Promise<void>;
   deleteReview(id: string): Promise<void>;
   getReview(id: string): Promise<Review | null>;
-  getReviewsOfBook(book_id: number): Promise<Review[]>;
+  getReviewsOfBook(book_id: number, keyword: string): Promise<Review[]>;
 }

添加搜索功能,infrastructure/database/mongo.ts

@@ -1,4 +1,11 @@
-import { MongoClient, Db, Collection, ObjectId } from "mongodb";
+import {
+  MongoClient,
+  Db,
+  Collection,
+  ObjectId,
+  Filter,
+  Document,
+} from "mongodb";
 import { Review } from "@/domain/model";
 import { ReviewManager } from "@/domain/gateway";
 
@@ -63,8 +70,15 @@ export class MongoPersistence implements ReviewManager {
     };
   }
 
-  async getReviewsOfBook(book_id: number): Promise<Review[]> {
-    const cursor = this.coll.find({ book_id });
+  async getReviewsOfBook(book_id: number, keyword: string): Promise<Review[]> {
+    const filter: Filter<Document> = { book_id };
+    if (keyword) {
+      filter.$or = [
+        { title: { $regex: keyword, $options: "i" } }, // Case-insensitive regex search for title
+        { content: { $regex: keyword, $options: "i" } }, // Case-insensitive regex search for content
+      ];
+    }
+    const cursor = this.coll.find(filter);
     const reviewDocs = await cursor.toArray();
     return reviewDocs.map((reviewDoc) => ({
       id: reviewDoc._id.toHexString(),

注意

正则表达式查询无法充分利用索引。虽然某些操作可能仍然从索引中受益,但与精确匹配前缀搜索相比,使用正则表达式可能效率较低。
如果你的集合包含大量文档,并且被搜索的字段没有建立索引,可能会导致查询性能较慢。

微调 application/executor/review_operator.ts

@@ -26,8 +26,8 @@ export class ReviewOperator {
     return await this.reviewManager.getReview(id);
   }
 
-  async getReviewsOfBook(book_id: number): Promise<Review[]> {
-    return await this.reviewManager.getReviewsOfBook(book_id);
+  async getReviewsOfBook(book_id: number, query: string): Promise<Review[]> {
+    return await this.reviewManager.getReviewsOfBook(book_id, query);
   }
 
   async updateReview(id: string, r: Review): Promise<Review> {

传入 query 参数,adapter/router.ts

@@ -100,7 +100,10 @@ class RestHandler {
     }
 
     try {
-      const books = await this.reviewOperator.getReviewsOfBook(bookID);
+      const books = await this.reviewOperator.getReviewsOfBook(
+        bookID,
+        req.query.q as string
+      );
       res.status(200).json(books);
     } catch (err) {
       console.error(`Failed to get reviews of book ${bookID}: ${err}`);

利用 mongoDB 实现搜索功能所需的更改已经全部加入。让我们测试一波。

使用 curl 尝试搜索书评

先加入一些书评数据:

curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Alice Johnson", "title": "A Timeless Classic", "content": "The Great Gatsby is a timeless classic that delves deep into the complexities of the human psyche and the pursuit of the American Dream."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Michael Adams", "title": "Brilliantly Written", "content": "Fitzgerald’s prose in The Great Gatsby is simply brilliant. Each sentence is crafted with care, drawing the reader into a world of opulence and tragedy."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Emily Parker", "title": "Mesmerizing", "content": "I was completely mesmerized by The Great Gatsby. Fitzgerald’s ability to create such vivid characters and evoke a sense of longing is unmatched."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Daniel White", "title": "Enthralling Plot", "content": "The plot of The Great Gatsby is enthralling from start to finish. It’s a story of love, loss, and the emptiness of the American Dream."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Sophia Lee", "title": "A Literary Gem", "content": "The Great Gatsby is a literary gem that shines with its insightful commentary on society and human nature. A must-read for all."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Ethan Miller", "title": "Timeless Masterpiece", "content": "The Great Gatsby remains a timeless masterpiece that continues to resonate with readers across generations. Fitzgerald’s prose is as relevant today as it was in the 1920s."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Olivia Wilson", "title": "Immersive Experience", "content": "Reading The Great Gatsby is an immersive experience like no other. Fitzgerald’s vivid descriptions transport you to the roaring twenties, making you feel like you’re part of the story."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Jacob Thompson", "title": "Intriguing Characters", "content": "What sets The Great Gatsby apart are its intriguing characters. Each one is flawed yet fascinating, contributing to the richness of the narrative."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Ava Martinez", "title": "Gripping Narrative", "content": "The Great Gatsby grips you from the first page and doesn’t let go until the very end. It’s a story that lingers in your mind long after you’ve finished reading."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Noah Taylor", "title": "Profound Themes", "content": "Beneath its glitzy surface, The Great Gatsby explores profound themes of love, betrayal, and the corrupting influence of wealth. A true masterpiece."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Isabella Hernandez", "title": "Hauntingly Beautiful", "content": "The Great Gatsby is hauntingly beautiful, painting a picture of an era filled with glamour and excess, yet tinged with sadness and longing."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Lucas Moore", "title": "Compelling Narrative", "content": "Fitzgerald weaves a compelling narrative in The Great Gatsby, drawing readers into the world of Jay Gatsby and Daisy Buchanan with finesse and skill."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Mia Clark", "title": "Unforgettable Characters", "content": "The characters in The Great Gatsby are unforgettable, each with their own desires and flaws that drive the story forward with intensity and emotion."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Elijah Garcia", "title": "Eloquent Prose", "content": "Fitzgerald’s eloquent prose in The Great Gatsby elevates the novel to literary greatness. It’s a book that demands to be savored and appreciated."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Charlotte King", "title": "Riveting Plot", "content": "The plot of The Great Gatsby is riveting, filled with twists and turns that keep you on the edge of your seat until the very end. An absolute page-turner."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "William Brown", "title": "Emotionally Resonant", "content": "The Great Gatsby is emotionally resonant, exploring themes of love and longing in a way that stays with you long after you’ve turned the final page."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Chloe Rodriguez", "title": "Sensory Delight", "content": "Reading The Great Gatsby is a sensory delight, with Fitzgerald’s vivid descriptions bringing the sights, sounds, and smells of the 1920s to life."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "James Lee", "title": "Thought-Provoking", "content": "The Great Gatsby is thought-provoking, challenging readers to reflect on the nature of wealth, ambition, and the pursuit of happiness."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Emma Taylor", "title": "Rich Symbolism", "content": "The Great Gatsby is rich in symbolism, with every detail serving a purpose in conveying deeper themes and messages about society and human nature."}' http://localhost:3000/reviews
curl -X POST -H "Content-Type: application/json" -d '{"book_id": 4, "author": "Ryan Martinez", "title": "A Literary Masterpiece", "content": "The Great Gatsby is undeniably a literary masterpiece, with its lyrical prose and timeless themes making it a must-read for all lovers of literature."}' http://localhost:3000/reviews

根据 title 和 content 搜索书评,关键字:masterpiece

curl -X GET "http://localhost:3000/books/4/reviews?q=masterpiece"

结果:

[
  {
    "id": "65e2d01909ef3f4e2f726f04",
    "book_id": 4,
    "author": "Ethan Miller",
    "title": "Timeless Masterpiece",
    "content": "The Great Gatsby remains a timeless masterpiece that continues to resonate with readers across generations. Fitzgerald’s prose is as relevant today as it was in the 1920s.",
    "created_at": "2024-03-02T07:07:05.291Z",
    "updated_at": "2024-03-02T07:07:05.291Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f08",
    "book_id": 4,
    "author": "Noah Taylor",
    "title": "Profound Themes",
    "content": "Beneath its glitzy surface, The Great Gatsby explores profound themes of love, betrayal, and the corrupting influence of wealth. A true masterpiece.",
    "created_at": "2024-03-02T07:07:05.358Z",
    "updated_at": "2024-03-02T07:07:05.358Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f12",
    "book_id": 4,
    "author": "Ryan Martinez",
    "title": "A Literary Masterpiece",
    "content": "The Great Gatsby is undeniably a literary masterpiece, with its lyrical prose and timeless themes making it a must-read for all lovers of literature.",
    "created_at": "2024-03-02T07:07:05.519Z",
    "updated_at": "2024-03-02T07:07:05.519Z"
  }
]

根据 title 和 content 搜索书评,关键字:Fitzgerald

curl -X GET "http://localhost:3000/books/4/reviews?q=Fitzgerald"

结果:

[
  {
    "id": "65e2d01909ef3f4e2f726f00",
    "book_id": 4,
    "author": "Michael Adams",
    "title": "Brilliantly Written",
    "content": "Fitzgerald’s prose in The Great Gatsby is simply brilliant. Each sentence is crafted with care, drawing the reader into a world of opulence and tragedy.",
    "created_at": "2024-03-02T07:07:05.226Z",
    "updated_at": "2024-03-02T07:07:05.226Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f01",
    "book_id": 4,
    "author": "Emily Parker",
    "title": "Mesmerizing",
    "content": "I was completely mesmerized by The Great Gatsby. Fitzgerald’s ability to create such vivid characters and evoke a sense of longing is unmatched.",
    "created_at": "2024-03-02T07:07:05.243Z",
    "updated_at": "2024-03-02T07:07:05.243Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f04",
    "book_id": 4,
    "author": "Ethan Miller",
    "title": "Timeless Masterpiece",
    "content": "The Great Gatsby remains a timeless masterpiece that continues to resonate with readers across generations. Fitzgerald’s prose is as relevant today as it was in the 1920s.",
    "created_at": "2024-03-02T07:07:05.291Z",
    "updated_at": "2024-03-02T07:07:05.291Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f05",
    "book_id": 4,
    "author": "Olivia Wilson",
    "title": "Immersive Experience",
    "content": "Reading The Great Gatsby is an immersive experience like no other. Fitzgerald’s vivid descriptions transport you to the roaring twenties, making you feel like you’re part of the story.",
    "created_at": "2024-03-02T07:07:05.307Z",
    "updated_at": "2024-03-02T07:07:05.307Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f0a",
    "book_id": 4,
    "author": "Lucas Moore",
    "title": "Compelling Narrative",
    "content": "Fitzgerald weaves a compelling narrative in The Great Gatsby, drawing readers into the world of Jay Gatsby and Daisy Buchanan with finesse and skill.",
    "created_at": "2024-03-02T07:07:05.390Z",
    "updated_at": "2024-03-02T07:07:05.390Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f0c",
    "book_id": 4,
    "author": "Elijah Garcia",
    "title": "Eloquent Prose",
    "content": "Fitzgerald’s eloquent prose in The Great Gatsby elevates the novel to literary greatness. It’s a book that demands to be savored and appreciated.",
    "created_at": "2024-03-02T07:07:05.423Z",
    "updated_at": "2024-03-02T07:07:05.423Z"
  },
  {
    "id": "65e2d01909ef3f4e2f726f0f",
    "book_id": 4,
    "author": "Chloe Rodriguez",
    "title": "Sensory Delight",
    "content": "Reading The Great Gatsby is a sensory delight, with Fitzgerald’s vivid descriptions bringing the sights, sounds, and smells of the 1920s to life.",
    "created_at": "2024-03-02T07:07:05.471Z",
    "updated_at": "2024-03-02T07:07:05.471Z"
  }
]

不错!基于 MySQL 和 mongoDB 的搜索功能已完成!

高级全文搜索

如果你想要拥有高级全文搜索支持,请尝试 ElasticsearchSolr。 这些解决方案针对文本搜索操作进行了优化,并提供诸如索引、相关性评分和语言特定的词干处理等功能。