Why should you care?

A festival sale might set discountPercent on all accessories, or a security fix sets mustResetPassword for a cohort of users.

See it live — copy this example

Open mongosh or MongoDB Compass, select database nosqlverse, then run the example. Change one field and run again.

db.products.insertMany([
  { name: "Mouse", category: "accessories", price: 599, sale: false },
  { name: "Pad", category: "accessories", price: 299, sale: false },
  { name: "SSD", category: "storage", price: 4000, sale: false }
])
db.products.updateMany(
  { category: "accessories" },
  { $set: { sale: true, discountPercent: 10 } }
)
db.products.find({ sale: true })

Run Example »

Edit the code below and click Run to see the result in Toolliyo’s live editor.

What happened?

• Only accessories match the filter.
• Both mouse and pad get sale true and discountPercent 10.
• SSD stays unchanged.
• find shows the two sale items.

Practice next

1. Seed the three products.
2. Run updateMany and note modifiedCount.
3. Verify storage product still has sale false.
4. Increase all sale prices with $mul (careful) or re-$set prices.
5. Add a second condition price: { $lt: 1000 }.

Remember

updateMany updates all matches. Filters must be precise. Ideal for bulk business rules.

Festival sale toggle

Flipkart merchandising enables sale:true on thousands of SKUs in one category overnight.

Outcome: Storefront reflects discounts without redeploying the app.