n8n/packages/nodes-base/nodes/Postgres/Postgres.node.ts

import { IExecuteFunctions } from 'n8n-core';
import {
	IDataObject,
	INodeExecutionData,
	INodeType,
	INodeTypeDescription,
	NodeOperationError,
} from 'n8n-workflow';

import * as pgPromise from 'pg-promise';

import { pgInsert, pgQuery, pgUpdate } from './Postgres.node.functions';

export class Postgres implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Postgres',
		name: 'postgres',
		icon: 'file:postgres.png',
		group: ['input'],
		version: 1,
		description: 'Gets, add and update data in Postgres.',
		defaults: {
			name: 'Postgres',
			color: '#336791',
		},
		inputs: ['main'],
		outputs: ['main'],
		credentials: [
			{
				name: 'postgres',
				required: true,
			},
		],
		properties: [
			{
				displayName: 'Operation',
				name: 'operation',
				type: 'options',
				options: [
					{
						name: 'Execute Query',
						value: 'executeQuery',
						description: 'Execute an SQL query',
					},
					{
						name: 'Insert',
						value: 'insert',
						description: 'Insert rows in database',
					},
					{
						name: 'Update',
						value: 'update',
						description: 'Update rows in database',
					},
				],
				default: 'insert',
				description: 'The operation to perform.',
			},

			// ----------------------------------
			//         executeQuery
			// ----------------------------------
			{
				displayName: 'Query',
				name: 'query',
				type: 'string',
				typeOptions: {
					rows: 5,
				},
				displayOptions: {
					show: {
						operation: ['executeQuery'],
					},
				},
				default: '',
				placeholder: 'SELECT id, name FROM product WHERE quantity > $1 AND price <= $2',
				required: true,
				description: 'The SQL query to execute. You can use n8n expressions or $1 and $2 in conjunction with query parameters.',
			},

			// ----------------------------------
			//         insert
			// ----------------------------------
			{
				displayName: 'Schema',
				name: 'schema',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['insert'],
					},
				},
				default: 'public',
				required: true,
				description: 'Name of the schema the table belongs to',
			},
			{
				displayName: 'Table',
				name: 'table',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['insert'],
					},
				},
				default: '',
				required: true,
				description: 'Name of the table in which to insert data to.',
			},
			{
				displayName: 'Columns',
				name: 'columns',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['insert'],
					},
				},
				default: '',
				placeholder: 'id:int,name:text,description',
				description:
					'Comma separated list of the properties which should used as columns for the new rows.<br>You can use type casting with colons (:) like id:int.',
			},

			// ----------------------------------
			//         update
			// ----------------------------------
			{
				displayName: 'Schema',
				name: 'schema',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['update'],
					},
				},
				default: 'public',
				required: false,
				description: 'Name of the schema the table belongs to',
			},
			{
				displayName: 'Table',
				name: 'table',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['update'],
					},
				},
				default: '',
				required: true,
				description: 'Name of the table in which to update data in',
			},
			{
				displayName: 'Update Key',
				name: 'updateKey',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['update'],
					},
				},
				default: 'id',
				required: true,
				description: 'Comma separated list of the properties which decides which rows in the database should be updated. Normally that would be "id".',
			},
			{
				displayName: 'Columns',
				name: 'columns',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['update'],
					},
				},
				default: '',
				placeholder: 'name:text,description',
				description:
					'Comma separated list of the properties which should used as columns for rows to update.<br>You can use type casting with colons (:) like id:int.',
			},

			// ----------------------------------
			//         insert,update
			// ----------------------------------
			{
				displayName: 'Return Fields',
				name: 'returnFields',
				type: 'string',
				displayOptions: {
					show: {
						operation: ['insert', 'update'],
					},
				},
				default: '*',
				description: 'Comma separated list of the fields that the operation will return',
			},
			// ----------------------------------
			//         Additional fields
			// ----------------------------------
			{
				displayName: 'Additional Fields',
				name: 'additionalFields',
				type: 'collection',
				placeholder: 'Add Field',
				default: {},
				options: [
					{
						displayName: 'Mode',
						name: 'mode',
						type: 'options',
						options: [
							{
								name: 'Independently',
								value: 'independently',
								description: 'Execute each query independently',
							},
							{
								name: 'Multiple queries',
								value: 'multiple',
								description: '<b>Default</b>. Sends multiple queries at once to database.',
							},
							{
								name: 'Transaction',
								value: 'transaction',
								description: 'Executes all queries in a single transaction',
							},
						],
						default: 'multiple',
						description: [
							'The way queries should be sent to database.',
							'Can be used in conjunction with <b>Continue on Fail</b>.',
							'See the docs for more examples',
						].join('<br>'),
					},
					{
						displayName: 'Query Parameters',
						name: 'queryParams',
						type: 'string',
						displayOptions: {
							show: {
								'/operation': [
									'executeQuery',
								],
							},
						},
						default: '',
						placeholder: 'quantity,price',
						description: 'Comma separated list of properties which should be used as query parameters.',
					},
				],
			},
		],
	};

	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
		const credentials = this.getCredentials('postgres');

		if (credentials === undefined) {
			throw new NodeOperationError(this.getNode(), 'No credentials got returned!');
		}

		const pgp = pgPromise();

		const config: IDataObject = {
			host: credentials.host as string,
			port: credentials.port as number,
			database: credentials.database as string,
			user: credentials.user as string,
			password: credentials.password as string,
		};

		if (credentials.allowUnauthorizedCerts === true) {
			config.ssl = {
				rejectUnauthorized: false,
			};
		} else {
			config.ssl = !['disable', undefined].includes(credentials.ssl as string | undefined);
			config.sslmode = (credentials.ssl as string) || 'disable';
		}

		const db = pgp(config);

		let returnItems = [];

		const items = this.getInputData();
		const operation = this.getNodeParameter('operation', 0) as string;

		if (operation === 'executeQuery') {
			// ----------------------------------
			//         executeQuery
			// ----------------------------------

			const queryResult = await pgQuery(this.getNodeParameter, pgp, db, items, this.continueOnFail());

			returnItems = this.helpers.returnJsonArray(queryResult);
		} else if (operation === 'insert') {
			// ----------------------------------
			//         insert
			// ----------------------------------

			const insertData = await pgInsert(this.getNodeParameter, pgp, db, items, this.continueOnFail());

			for (let i = 0; i < insertData.length; i++) {
				returnItems.push({
					json: insertData[i],
				});
			}
		} else if (operation === 'update') {
			// ----------------------------------
			//         update
			// ----------------------------------

			const updateItems = await pgUpdate(this.getNodeParameter, pgp, db, items, this.continueOnFail());

			returnItems = this.helpers.returnJsonArray(updateItems);
		} else {
			await pgp.end();
			throw new NodeOperationError(this.getNode(), `The operation "${operation}" is not supported!`);
		}

		// Close the connection
		await pgp.end();

		return this.prepareOutputData(returnItems);
	}
}