One Table to Rule Them All
OneTable is the most evolved API for DynamoDB. It provides a dry, high-level, elegant syntax while enabling full access to the DynamoDB API.
OneTable works with AWS V2 and V3 SDKs for JavaScript and TypeScript. For TypeScript, OneTable will create fully typed entities from your data schemas automatically.
npm i dynamodb-onetable
Import the OneTable library. If you are not using ES modules or TypeScript, use require
to import the libraries.
import {Table} from 'dynamodb-onetable'
If you are using the AWS SDK V3, import the AWS V3 DynamoDBClient
class. Then create a DynamoDBClient
instance.
import {DynamoDBClient} from '@aws-sdk/client-dynamodb'
const client = new DynamoDBClient(params)
If you are using the legacy AWS SDK V2, import the AWS DynamoDB
class and create a DocumentClient
instance.
import DynamoDB from 'aws-sdk/clients/dynamodb'
const client = new DynamoDB.DocumentClient(params)
Note: you can use the Table.setClient API to defer setting the client or replace the client at any time.
Initialize your OneTable Table
instance and define your models via a schema.
const table = new Table({
client: client,
name: 'MyTable',
schema: MySchema,
})
This will initialize your OneTable Table instance and define your models via a schema.
Schemas define how items will be stored in your database and look like this:
const MySchema = {
format: 'onetable:1.1.0',
version: '0.0.1',
indexes: {
primary: {hash: 'pk', sort: 'sk'},
gs1: {hash: 'gs1pk', sort: 'gs1sk', follow: true},
ls1: {sort: 'id', type: 'local'},
},
models: {
Account: {
pk: {type: String, value: 'account:${id}'},
sk: {type: String, value: 'account:'},
id: {type: String, generate: 'ulid', validate: /^[0123456789ABCDEFGHJKMNPQRSTVWXYZ]{26}$/i},
name: {type: String, required: true},
status: {type: String, default: 'active'},
zip: {type: String},
},
User: {
pk: {type: String, value: 'account:${accountName}'},
sk: {type: String, value: 'user:${email}', validate: EmailRegExp},
id: {type: String, required: true},
accountName: {type: String, required: true},
email: {type: String, required: true},
firstName: {type: String, required: true},
lastName: {type: String, required: true},
username: {type: String, required: true},
role: {type: String, enum: ['user', 'admin'], required: true, default: 'user'},
balance: {type: Number, default: 0},
gs1pk: {type: String, value: 'user-email:${email}'},
gs1sk: {type: String, value: 'user:'},
},
},
params: {
isoDates: true,
timestamps: true,
},
}
To create an item:
let account = await Account.create({
id: '8e7bbe6a-4afc-4117-9218-67081afc935b',
name: 'Acme Airplanes',
})
This will write the following to DynamoDB:
{
pk: 'account:8e7bbe6a-4afc-4117-9218-67081afc935b',
sk: 'account:98034',
id: '8e7bbe6a-4afc-4117-9218-67081afc935b',
name: 'Acme Airplanes',
status: 'active',
zip: '98034',
created: 1610347305510,
updated: 1610347305510,
}
Get an item:
let account = await Account.get({
id: '8e7bbe6a-4afc-4117-9218-67081afc935b',
})
which will return:
{
id: '8e7bbe6a-4afc-4117-9218-67081afc935b',
name: 'Acme Airplanes',
status: 'active',
zip: '98034',
}
To use a secondary index:
let user = await User.get({email: 'user@example.com'}, {index: 'gs1'})
To find a set of items:
let users = await User.find({accountId: account.id})
let adminUsers = await User.find({accountId: account.id, role: 'admin'})
let users = await User.find(
{accountId: account.id},
{
where: '${balance} > {100.00}',
}
)
// Get a count of matching users without returning the actual items
let users = await User.find({accountId: account.id, role: 'admin'}, {count: true})
let count = users.count
To update an item:
await User.update({id: userId, balance: 50})
await User.update({id: userId}, {add: {balance: 10.0}})
await User.update({id: userId}, {set: {status: '{active}'}})
To do a transactional update:
let transaction = {}
await Account.update({id: account.id, status: 'active'}, {transaction})
await User.update({id: user.id, role: 'user'}, {transaction})
await table.transact('write', transaction)
OneTable provides TypeScript type declaration files so that OneTable APIs, requests and responses can be fully type checked.
OneTable also creates type declarations for your table entities and attributes. TypeScript will catch any invalid entity or entity attribute references.
Using the magic of TypeScript dynamic typing, OneTable automatically converts your OneTable schema into fully typed generic Model APIs.
For example:
import {Entity, Model, Table} from 'dynamodb-onetable'
const MySchema = {
...
models: {
Account: {
pk: { type: String, value: 'account:${name}' },
name: { type: String },
}
} as const // Required for TypeScript
}
// Fully typed Account object based on the schema
type Account = Entity<typeof MySchema.models.Account>
let account: Account = {
name: 'Coyote', // OK
unknown: 42, // Error
}
let AccountModel: Model<Account> = table.getModel('Account')
let account = await AccountModel.create({
name: 'Acme', // OK
unknown: 42, // Error
})
account.name = 'Coyote' // OK
account.unknown = 42 // Error
Here is a collection of articles that can help you on your way with DynamoDB and OneTable.
And a few serverless articles:
Serverless Topic | Link |
---|---|
How to Debug Serverless Apps | https://www.sensedeep.com/blog/posts/stories/how-to-debug-serverless-apps.html |
How to invoke HTTP without Waiting from Lambda | https://www.sensedeep.com/blog/posts/stories/lambda-fast-http.html |
Fast Logging with Lambda | https://www.sensedeep.com/blog/posts/senselogs/serverless-logging.html |
Please try our SenseDeep Serverless Developer Studio that includes a full DynamoDB suite with single-table aware data browser, single-table designer, migration manager, provisioning planner and metrics.
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