@dandi/data

The @dandi/data package provides basic types and helpers for data
clients that connect databases and other data providers to your Dandi
application. These types provide a standard interface for working with
external data within Dandi.

Implementations

The interfaces defined in @dandi/data are intended to allow wrapping
existing database client implementations (e.g. node-postgres) and
extending their functionality with Dandi.

Configuration

Use a @dandi/config configuration provider to supply connection and
authentication information to the @dandi/data client. This example
uses AwsSsmConfigClient and the @dandi-contrib/data-pg client.

``typescript
import { AwsSsmConfigClient } from '@dandi-contrib/config-aws-ssm'
import { DandiApplication } from '@dandi/core'
import { PgDbModule } from '@dandi-contrib/data-pg'

const myApp = new DandiApplication({
providers: [

...

// database
PgDbModule,

AwsSsmConfigClient.provider(DbConnectionInfo.configToken(myapp-postgres-connection-info)),
AwsSsmConfigClient.provider(DbUserCredentials.configToken(myapp-postgres-credentials)),

...

],
})
`

API Reference

This reference describes the generic interfaces defined by @dandi/data.
Each implementation may vary, but this documentation describes the
intention of the interfaces.

$3

A model for describing connection info for a database connection. Used
with @dandi/config to allow retrieving from a configuration provider
like AWS SSM (see @dandi-contrib/config-aws-ssm.

$3

A model for describing user credentials for authenticating with a
database. Used with @dandi/config to allow retrieving from a
configuration provider like AWS SSM (see
@dandi-contrib/config-aws-ssm.

$3

The most basic client interface for working with a database.

- query(cmd: string, ...args: any[]): Promise - sends a
parameterized query to the underlying database client and returns
the resulting rows directly, without any model conversion or
validation.

- queryModel(model: Constructor, cmd: string, ...args: any[]): Promise -
sends a parameterized query to the underlying database client and
returns all rows, converting (and optionally validating) each row using
the configured ModelBuilder.

- queryModelSingle(model: Constructor, cmd: string, ...args: any[]): Promise -
same as queryModel, but only returns the first row. Throws a
PgDbMultipleResultsError if more than one row is returned by the
database. Returns null if no rows are returned.

$3

Extends DbQueryable to allow using transactions.

- transaction(transactionFn: TransactionFn): Promise -
initiates a database transaction, creates a DbTransactionClient
instance, and uses it to invoke the provided transactionFn.

$3

An extension of DbQueryable that is used during a transaction. Also
extends Disposable. The transaction is automatically committed during
dispose() unless an exception is thrown, in which case it is
automatically rolled back.

- commit() - commits the transaction.
- rollback() - rolls back the transaction.

Transaction Example

`typescript
export class MyModelManager {
constructor(@Inject(DbClient) private dbClient: DbClient) {}

public addModel(model: MyModelRequest): Promise {
return this.dbClient.transaction(async (tran) => {
const query1 = await tran.queryModelSingle(MyModel, INSERT_QUERY, model.name)
const query2 = await tran.query(INSERT_MODEL_PERMISSION)
return query1
})
}
}
``