Pagination pattern with skip and limit in MongoDB

Introduction

Pagination helps you see data in small parts instead of all at once. It makes browsing big lists easier and faster.

When showing a list of products on a website page by page.

When displaying user comments in chunks instead of all at once.

When loading search results gradually to save time and data.

When you want to let users jump to a specific page of data.

When handling large collections to avoid slow loading.

Syntax

MongoDB

db.collection.find(query).skip(number_to_skip).limit(number_to_show)

Use skip to jump over a number of documents.

Use limit to set how many documents to return.

Examples

Get the first 5 products (page 1).

MongoDB

db.products.find().skip(0).limit(5)

Get the next 5 products (page 2), skipping the first 5.

MongoDB

db.products.find().skip(5).limit(5)

Get 10 active users, skipping the first 10 active users.

MongoDB

db.users.find({active: true}).skip(10).limit(10)

Sample Program

This query shows products on page 3, with 4 products per page. It skips the first 8 products and shows the next 4.

MongoDB

use shopdb

// Show page 3 of products, 4 items per page
const page = 3;
const perPage = 4;
const skipCount = (page - 1) * perPage;
db.products.find().skip(skipCount).limit(perPage).forEach(doc => printjson(doc));

Important Notes

Skipping many documents can slow down queries on large collections.

Use indexes to speed up pagination queries.

For very large data, consider other pagination methods like range queries.

Summary

Pagination divides data into pages using skip and limit.

skip jumps over documents, limit sets how many to show.

Good for showing data in small, easy-to-handle parts.

Practice

1.

What does the skip method do in MongoDB pagination?

easy

A. It limits the number of documents returned.

B. It deletes documents from the collection.

C. It sorts the documents in ascending order.

D. It skips a specified number of documents before returning results.

Solution

1. Step 1: Understand the role of skip

   The skip method tells MongoDB to ignore a certain number of documents from the start of the result set.

2. Step 2: Compare with other methods

   limit controls how many documents to return, not skipping. Sorting and deleting are unrelated to skip.

3. Final Answer:

   It skips a specified number of documents before returning results. -> Option D

4. Quick Check:

   skip = skip documents [OK]

Hint: Skip jumps over documents, limit sets how many to show [OK]

Common Mistakes:

• Confusing skip with limit
• Thinking skip sorts documents
• Assuming skip deletes documents

2.

Which of the following is the correct syntax to get the second page of results with 5 documents per page in MongoDB?

db.collection.find().skip(?).limit(?)

easy

A. skip(1).limit(5)

B. skip(10).limit(5)

C. skip(5).limit(5)

D. skip(0).limit(5)

Solution

1. Step 1: Calculate skip value for page 2

   Each page has 5 documents, so page 1 skips 0, page 2 skips 5 documents (5 * (2-1) = 5).

2. Step 2: Set limit to page size

   Limit should be 5 to get 5 documents per page.

3. Final Answer:

   skip(5).limit(5) -> Option C

4. Quick Check:

   Page 2 skip = 5, limit = 5 [OK]

Hint: Skip = pageSize * (pageNumber - 1), limit = pageSize [OK]

Common Mistakes:

• Using skip(10) for page 2
• Setting skip to 1 instead of 5
• Confusing skip and limit values

3.

Given a collection with documents numbered 1 to 10, what documents will this query return?

db.collection.find().skip(3).limit(4)

medium

A. Documents 1 to 4

B. Documents 4 to 7

C. Documents 3 to 6

D. Documents 5 to 8

Solution

1. Step 1: Understand skip(3)

   Skip the first 3 documents: documents 1, 2, and 3 are ignored.

2. Step 2: Apply limit(4)

   Return the next 4 documents after skipping: documents 4, 5, 6, and 7.

3. Final Answer:

   Documents 4 to 7 -> Option B

4. Quick Check:

   Skip 3, then limit 4 = docs 4-7 [OK]

Hint: Skip removes first N, limit picks next M documents [OK]

Common Mistakes:

• Counting skip as inclusive
• Starting limit count before skip
• Off-by-one errors in document numbers

4.

Identify the error in this pagination query to get page 3 with 10 documents per page:

db.collection.find().skip(20).limit(20)

medium

A. limit should be 10, not 20

B. skip value is too high

C. skip should be 30 for page 3

D. No error, query is correct

Solution

1. Step 1: Calculate correct skip and limit for page 3

   Skip should be 10 * (3-1) = 20, which is correct here.

2. Step 2: Check limit value

   Limit should be 10 to get 10 documents per page, but query uses limit(20), which is too many.

3. Final Answer:

   limit should be 10, not 20 -> Option A

4. Quick Check:

   Limit = page size = 10 [OK]

Hint: Limit equals page size, skip = pageSize*(page-1) [OK]

Common Mistakes:

• Setting limit equal to skip
• Using skip as page number
• Assuming no limit needed

5.

You want to display page 4 of a product list with 8 items per page. However, the total products are 30. Which query correctly handles this pagination without returning empty results?

db.products.find().skip(?).limit(?)

hard

A. skip(24).limit(8)

B. skip(32).limit(8)

C. skip(16).limit(8)

D. skip(30).limit(8)

Solution

1. Step 1: Calculate skip for page 4

   Skip = 8 * (4-1) = 24 documents to reach page 4.

2. Step 2: Check total documents and limit

   Total is 30, so skipping 24 leaves 6 documents (30-24). Limit 8 is okay; it will return only available 6 documents without error.

3. Step 3: Analyze other options

   skip(32) and skip(30) exceed total documents, returning empty results. skip(16) is for page 3, not page 4.

4. Final Answer:

   skip(24).limit(8) -> Option A

5. Quick Check:

   Page 4 skip = 24, limit = 8, total 30 [OK]

Hint: Skip = pageSize*(page-1), limit = pageSize, check total docs [OK]

Common Mistakes:

• Skipping beyond total documents
• Using wrong skip for page number
• Ignoring total document count