What is a keyPath and how is it used in IndexedDB?

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ICSM Computer · Answer

In IndexedDB, a keyPath is a property (or path) within your stored object that serves as its
primary key — a unique identifier for each record.
What is keyPath?
It's a string or array that tells IndexedDB which property of the object should be used as the key.This key must be unique in the object store.You define it when creating the object store.
How keyPath is Used
Example: Simple KeyPath
const request = indexedDB.open('MyDB', 1);
request.onupgradeneeded = (e) =andgt; {
    const db = e.target.result;
    // Use 'id' as the keyPath
    db.createObjectStore('users', { keyPath: 'id' });
};
Now, when you store an object like this:
store.add({ id: 101, name: "Alice" });
IndexedDB uses 101 (from id) as the primary key.
Example: Nested KeyPath
db.createObjectStore('orders', { keyPath: 'order.id' });
Here, the object:
{ order: { id: 999 }, item: "Pen" }
Will be stored with 999 as the key.
Example: Compound KeyPath
db.createObjectStore('contacts', { keyPath: ['firstName', 'lastName'] });
Now the combination of firstName and lastName is the unique key.
store.add({ firstName: "John", lastName: "Doe", email: "john@example.com" });
// Key: ["John", "Doe"]
Without keyPath (Manual Keys)
If you don’t use a keyPath, you must pass the key manually:
const store = db.createObjectStore('notes'); // No keyPath
store.add({ title: "Reminder" }, 1); // '1' is the key
Summary
Term
Meaning
keyPath
A field name (or array of names) in your object used as key
Purpose
Tells IndexedDB where to find the key inside the object
Benefit
No need to pass the key manually during add() or put()

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What is a keyPath and how is it used in IndexedDB?

ICSM Computer

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1 Answers

What is `keyPath`?

How `keyPath` is Used

Example: Simple KeyPath

Example: Nested KeyPath

Example: Compound KeyPath

Without `keyPath` (Manual Keys)

Summary

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Term	Meaning
`keyPath`	A field name (or array of names) in your object used as key
Purpose	Tells IndexedDB where to find the key inside the object
Benefit	No need to pass the key manually during `add()` or `put()`