How do you implement text search in MongoDB? | MongoDB Interview Questions

What You'll Learn

Creating text indexes
Text search queries
Search score and relevance

Create Text Index

code.jsJavaScript

// Single field
db.articles.createIndex({ content: "text" });

// Multiple fields
db.articles.createIndex({ title: "text", content: "text" });

// With weights
db.articles.createIndex(
  { title: "text", content: "text" },
  { weights: { title: 10, content: 1 } }
);

Basic Text Search

code.jsJavaScript

// Search for words
db.articles.find({ $text: { $search: "mongodb tutorial" } });

// Phrase search (exact match)
db.articles.find({ $text: { $search: '"mongodb tutorial"' } });

// Exclude words
db.articles.find({ $text: { $search: "mongodb -mysql" } });

Search Score

code.jsJavaScript

// Get relevance score
db.articles.find(
  { $text: { $search: "mongodb" } },
  { score: { $meta: "textScore" } }
).sort({ score: { $meta: "textScore" } });

Mongoose Implementation

code.jsJavaScript

const articleSchema = new mongoose.Schema({
  title: String,
  content: String
});

articleSchema.index({ title: 'text', content: 'text' });

// Search
const results = await Article.find(
  { $text: { $search: query } },
  { score: { $meta: 'textScore' } }
)
.sort({ score: { $meta: 'textScore' } })
.limit(10);

Limitations

One text index per collection
Case-insensitive by default
No partial word matching
Consider Elasticsearch for advanced needs