Simple DynamoDB

A simple wrapper to help you work with DynamoDB. Used to live as copy pasta in all my projects, decided to make it open source so I can keep making it better.

Here is a full tutorial building an example CRUD API with Simple DynamoDB 👉 Serverless Handbook: REST API

Installation

yarn add simple-dynamodb

Import as:

import * as db from "simple-dynamodb";

for best ease of use. The rest of this README assumes you're importing like this :)

Methods

These are thin wrappers on native AWS SDK DynamoDB functions. Promisified for easier use and with sensible defaults for code readability.

getItem

getItem reads specific items from your database.

const item = await db.getItem({
    TableName: process.env.ITEM_TABLE!,
    Key: { itemId }
});

console.log(item.Item);

updateItem

updateItem upserts items into your database and returns the entire object by default.

const item = await db.updateItem({
    TableName: process.env.ITEM_TABLE!,
    Key: { itemId },
    UpdateExpression: `SET ${db.buildExpression(body)}`,
    ExpressionAttributeValues: {
        ...db.buildAttributes(body)
    }
    // default ReturnValues: "ALL_NEW"
});

console.log(item.Attributes);

buildExpression

Helper method to turn a { key: value } object into a DynamoDB expression.

Use it in your SET or other expressions as a string fragment. Add your own custom values on top.

UpdateExpression: `SET ${db.buildExpression(body)}`,

buildAttributes

Helper method to turn a { key: value } object into a DynamoDB attributes list.

Use it for your ExpressionAttributeValues and add your own custom values on top.

ExpressionAttributeValues: {
    ...db.buildAttributes(body)
}

deleteItem

Deletes an item from your database and returns its old values by default.

const item = await db.deleteItem({
    TableName: process.env.ITEM_TABLE!,
    Key: { itemId }
    // default ReturnValues: "ALL_OLD"
});

console.log(item.Attributes);

scanItems

Used for searching through your database table.

// to get all values from a table
const result = await db.scanItems({
    TableName: process.env.ITEM_TABLE!
});

console.log(result.Items);

To filter based on params, you can do something like this:

const searchBy = {
    userId
}

const result = await db.scanItems({
    TableName: process.env.ITEM_TABLE!,
    FilterExpression: `#user = :userId`,
    ExpressionAttributeNames: {
        "#user": "userId"
    },
    ExpressionAttributeValues: {
        ...db.buildAttributes(searchBy)
    }
}

console.log(result.Items)

Author

👤 Swizec Teller swizec@swizec.com

• Github: @swizec
• Twitter: @swizec
• Blog: swizec.com/blog

🤝 Contributing

Contributions, issues and feature requests are welcome!
Feel free to check issues page.

I am looking to support other authentication providers. Please help :)

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📝 License

Copyright © 2020 Swizec Teller swizec@swizec.com.
This project is MIT licensed.