feat(Merge Node): Overhaul, v3 (#9528)

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>
Co-authored-by: Shireen Missi <94372015+ShireenMissi@users.noreply.github.com>

packages/nodes-base/nodes/Merge/v3/actions/mode/combineBySql.ts

@@ -0,0 +1,137 @@
+import type {
+	IDataObject,
+	IExecuteFunctions,
+	INodeExecutionData,
+	INodeProperties,
+	IPairedItemData,
+} from 'n8n-workflow';
+import { NodeOperationError } from 'n8n-workflow';
+
+import { getResolvables, updateDisplayOptions } from '@utils/utilities';
+import { numberInputsProperty } from '../../helpers/descriptions';
+
+import alasql from 'alasql';
+import type { Database } from 'alasql';
+
+export const properties: INodeProperties[] = [
+	numberInputsProperty,
+	{
+		displayName: 'Query',
+		name: 'query',
+		type: 'string',
+		default: 'SELECT * FROM input1 LEFT JOIN input2 ON input1.name = input2.id',
+		noDataExpression: true,
+		description: 'Input data available as tables with corresponding number, e.g. input1, input2',
+		hint: 'Supports <a href="https://github.com/alasql/alasql/wiki/Supported-SQL-statements" target="_blank">most</a> of the SQL-99 language',
+		required: true,
+		typeOptions: {
+			rows: 5,
+			editor: 'sqlEditor',
+		},
+	},
+];
+
+const displayOptions = {
+	show: {
+		mode: ['combineBySql'],
+	},
+};
+
+export const description = updateDisplayOptions(displayOptions, properties);
+
+export async function execute(
+	this: IExecuteFunctions,
+	inputsData: INodeExecutionData[][],
+): Promise<INodeExecutionData[]> {
+	const nodeId = this.getNode().id;
+	const returnData: INodeExecutionData[] = [];
+	const pairedItem: IPairedItemData[] = [];
+
+	const db: typeof Database = new (alasql as any).Database(nodeId);
+
+	try {
+		for (let i = 0; i < inputsData.length; i++) {
+			const inputData = inputsData[i];
+
+			inputData.forEach((item, index) => {
+				if (item.pairedItem === undefined) {
+					item.pairedItem = index;
+				}
+
+				if (typeof item.pairedItem === 'number') {
+					pairedItem.push({
+						item: item.pairedItem,
+						input: i,
+					});
+					return;
+				}
+
+				if (Array.isArray(item.pairedItem)) {
+					const pairedItems = item.pairedItem
+						.filter((p) => p !== undefined)
+						.map((p) => (typeof p === 'number' ? { item: p } : p))
+						.map((p) => {
+							return {
+								item: p.item,
+								input: i,
+							};
+						});
+					pairedItem.push(...pairedItems);
+					return;
+				}
+
+				pairedItem.push({
+					item: item.pairedItem.item,
+					input: i,
+				});
+			});
+
+			db.exec(`CREATE TABLE input${i + 1}`);
+			db.tables[`input${i + 1}`].data = inputData.map((entry) => entry.json);
+		}
+	} catch (error) {
+		throw new NodeOperationError(this.getNode(), error, {
+			message: 'Issue while creating table from',
+			description: error.message,
+			itemIndex: 0,
+		});
+	}
+
+	try {
+		let query = this.getNodeParameter('query', 0) as string;
+
+		for (const resolvable of getResolvables(query)) {
+			query = query.replace(resolvable, this.evaluateExpression(resolvable, 0) as string);
+		}
+
+		const result: IDataObject[] = db.exec(query);
+
+		for (const item of result) {
+			if (Array.isArray(item)) {
+				returnData.push(...item.map((json) => ({ json, pairedItem })));
+			} else if (typeof item === 'object') {
+				returnData.push({ json: item, pairedItem });
+			}
+		}
+
+		if (!returnData.length) {
+			returnData.push({ json: { success: true }, pairedItem });
+		}
+	} catch (error) {
+		let message = '';
+		if (typeof error === 'string') {
+			message = error;
+		} else {
+			message = error.message;
+		}
+		throw new NodeOperationError(this.getNode(), error, {
+			message: 'Issue while executing query',
+			description: message,
+			itemIndex: 0,
+		});
+	}
+
+	delete alasql.databases[nodeId];
+
+	return returnData;
+}