n8n/packages/nodes-base/nodes/Postgres/v2/actions/router.ts

import type { IExecuteFunctions, INodeExecutionData } from 'n8n-workflow';
import { NodeExecutionOutput, NodeOperationError } from 'n8n-workflow';

import { configurePostgres } from '../transport';
import { configureQueryRunner } from '../helpers/utils';
import type { PostgresNodeCredentials, PostgresNodeOptions } from '../helpers/interfaces';
import type { PostgresType } from './node.type';

import * as database from './database/Database.resource';

export async function router(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
	let returnData: INodeExecutionData[] = [];

	const items = this.getInputData();
	const resource = this.getNodeParameter<PostgresType>('resource', 0);
	const operation = this.getNodeParameter('operation', 0);

	const credentials = (await this.getCredentials('postgres')) as PostgresNodeCredentials;
	const options = this.getNodeParameter('options', 0, {}) as PostgresNodeOptions;
	const node = this.getNode();
	options.nodeVersion = node.typeVersion;
	options.operation = operation;

	const { db, pgp } = await configurePostgres.call(this, credentials, options);

	const runQueries = configureQueryRunner.call(
		this,
		this.getNode(),
		this.continueOnFail(),
		pgp,
		db,
	);

	const postgresNodeData = {
		resource,
		operation,
	} as PostgresType;

	try {
		switch (postgresNodeData.resource) {
			case 'database':
				returnData = await database[postgresNodeData.operation].execute.call(
					this,
					runQueries,
					items,
					options,
					db,
				);
				break;
			default:
				throw new NodeOperationError(
					this.getNode(),
					`The operation "${operation}" is not supported!`,
				);
		}
	} finally {
		if (!db.$pool.ending) await db.$pool.end();
	}

	if (operation === 'select' && items.length > 1 && !node.executeOnce) {
		return new NodeExecutionOutput(
			[returnData],
			[
				{
					message: `This node ran ${items.length} times, once for each input item. To run for the first item only, enable 'execute once' in the node settings`,
					location: 'outputPane',
				},
			],
		);
	}

	return [returnData];
}