Amplify GraphQL Relational Schema Transformer

import { AmplifyGraphqlApi, AmplifyGraphqlDefinition } from '@aws-amplify/graphql-api-construct';
import { App, Stack } from 'aws-cdk-lib';
import { CfnParameter } from 'aws-cdk-lib';

const app = new App();
const stack = new Stack(app, 'MyAmplifyRelationalApiStack');

// Define your database connection details using CDK parameters or environment variables.
// In a real application, retrieve these securely (e.g., from AWS Secrets Manager).
const dbHost = new CfnParameter(stack, 'DbHost', { type: 'String', description: 'Database Hostname' }).valueAsString;
const dbName = new CfnParameter(stack, 'DbName', { type: 'String', description: 'Database Name' }).valueAsString;
const dbUser = new CfnParameter(stack, 'DbUser', { type: 'String', description: 'Database User' }).valueAsString;
const dbPassword = new CfnParameter(stack, 'DbPassword', { type: 'String', description: 'Database Password', noEcho: true }).valueAsString;

// A simplified GraphQL schema for a relational model.
// In a typical Amplify CLI workflow, this would be in `amplify/backend/api/<api-name>/schema.sql.graphql`
const relationalSchema = `
  type Post @model @hasMany(references: "Author") {
    id: ID!
    title: String!
    content: String
    authorId: ID
    author: Author @belongsTo(references: "Post")
  }

  type Author @model {
    id: ID!
    name: String!
    email: String!
    posts: [Post]
  }

  # Example of how to connect to an existing database table (e.g., in schema.sql.graphql)
  # Note: The actual connection parameters are provided at deployment time,
  # not directly in the GraphQL schema directives for relational sources.
`;

new AmplifyGraphqlApi(stack, 'MyRelationalApi', {
  apiName: 'myRelationalApi',
  definition: AmplifyGraphqlDefinition.fromString(relationalSchema, {
    // These are example settings; actual implementation varies by database and security setup.
    // The transformer would infer schema from the live database during 'amplify push'
    // or when using `amplify import api` via Amplify CLI.
    // For CDK, you might define the RDS data source and connect it.
    // This part is highly dependent on how your RDS instance is managed and exposed.
    database: {
      engine: 'MYSQL',
      vpcConfig: {
        vpcId: 'vpc-xxxxxxxxxxxxx', // Replace with your VPC ID
        securityGroupIds: ['sg-xxxxxxxxxxxxx'], // Replace with your Security Group ID
        subnetIds: ['subnet-xxxxxxxxxxxxx', 'subnet-yyyyyyyyyyyyy'], // Replace with your Subnet IDs
      },
      clusterIdentifier: 'my-rds-cluster',
      secretArn: 'arn:aws:secretsmanager:REGION:ACCOUNT:secret:rds-credentials-xxxxxx' // Example
    }
  })
});

app.synth();