kysely update many

Guri Bee

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22-10-2024

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Mastering Database Updates with Kysely: A Guide to Updating Multiple Records

Kysely, a modern TypeScript ORM for Node.js and Deno, offers a powerful and type-safe way to interact with your databases. One of its key strengths lies in its ability to efficiently update multiple records. This article delves into the world of Kysely's updateMany method and explores its capabilities through practical examples.

Understanding updateMany

The updateMany method, as its name suggests, enables you to modify multiple records within a table based on a specified condition. It provides a clear and expressive syntax for defining your update operation, ensuring type safety and preventing potential errors.

Let's examine the core structure of updateMany:

db.updateMany('users').set({ name: 'New Name' }).where('id', '=', 1);

Here's a breakdown:

1. db.updateMany('users'): We begin by targeting the 'users' table for update operations.
2. .set({ name: 'New Name' }): This defines the update statement. We're setting the 'name' column to 'New Name' for the selected records.
3. .where('id', '=', 1): This clause specifies the condition for selecting the records to update. Here, we are targeting records where the 'id' column equals 1.

Practical Examples:

Updating User Information:

import { Kysely } from 'kysely';

// Database connection setup (example)
const db = new Kysely({
  dialect: 'mysql',
  db: {
    host: 'localhost',
    user: 'root',
    password: 'password',
    database: 'my_database'
  }
});

// Update all users with the 'admin' role to have 'active' status
async function updateAdminStatus() {
  await db.updateMany('users')
    .set({ status: 'active' })
    .where('role', '=', 'admin');
}

updateAdminStatus();

In this example, we update the 'status' column of all users with the 'admin' role to 'active'. Kysely ensures that only users with the 'admin' role are affected, preventing unintended data modifications.

Updating Product Prices:

async function updateProductPrices() {
  // Increase the price of all products by 10%
  await db.updateMany('products')
    .set({ price: (product) => product.price * 1.1 })
    .where('category', '=', 'electronics');
}

updateProductPrices();

This example demonstrates how to update prices dynamically based on existing data. The set method allows us to use a function to determine the new price, effectively increasing the price of all electronic products by 10%.

Beyond the Basics:

1. Chainable Operations:

Kysely supports chaining methods for further customization. For example:

db.updateMany('users')
  .set({ name: 'New Name' })
  .where('id', '=', 1)
  .returning('id'); // Return the ID of the updated records

2. Conditional Updates:

Use the returning method to retrieve information about the affected rows.

const result = await db.updateMany('users')
  .set({ status: 'inactive' })
  .where('last_login', '<', new Date()) // Update users who haven't logged in recently
  .returning('id');

console.log(result); // View the IDs of the updated records

3. Type Safety:

One of Kysely's key strengths is its type safety. It helps prevent runtime errors by ensuring that your update operations match the structure of your database tables.

4. Performance:

Kysely optimizes queries for performance, ensuring that your updates are executed efficiently.

Conclusion:

Kysely's updateMany method is a powerful tool for efficiently updating multiple records in your database. Its clear syntax, chainable operations, and type safety make it a reliable choice for managing data modifications in your Node.js and Deno applications. By leveraging these capabilities, you can ensure that your updates are accurate, performant, and easy to maintain.