feat(Postgres Node): Overhaul node

packages/nodes-base/nodes/Postgres/v2/methods/loadOptions.ts

@@ -0,0 +1,46 @@
+import type { ILoadOptionsFunctions, INodePropertyOptions } from 'n8n-workflow';
+import type { ConnectionsData } from '../helpers/interfaces';
+import { getTableSchema } from '../helpers/utils';
+import { Connections } from '../transport';
+
+export async function getColumns(this: ILoadOptionsFunctions): Promise<INodePropertyOptions[]> {
+	const credentials = await this.getCredentials('postgres');
+
+	const { db } = (await Connections.getInstance(credentials)) as ConnectionsData;
+
+	const schema = this.getNodeParameter('schema', 0, {
+		extractValue: true,
+	}) as string;
+
+	const table = this.getNodeParameter('table', 0, {
+		extractValue: true,
+	}) as string;
+
+	try {
+		const columns = await getTableSchema(db, schema, table);
+
+		return columns.map((column) => ({
+			name: column.column_name,
+			value: column.column_name,
+			description: `Type: ${column.data_type.toUpperCase()}, Nullable: ${column.is_nullable}`,
+		}));
+	} catch (error) {
+		throw error;
+	}
+}
+
+export async function getColumnsMultiOptions(
+	this: ILoadOptionsFunctions,
+): Promise<INodePropertyOptions[]> {
+	const returnData = await getColumns.call(this);
+	const returnAll = { name: '*', value: '*', description: 'All columns' };
+	return [returnAll, ...returnData];
+}
+
+export async function getColumnsWithoutColumnToMatchOn(
+	this: ILoadOptionsFunctions,
+): Promise<INodePropertyOptions[]> {
+	const columnToMatchOn = this.getNodeParameter('columnToMatchOn') as string;
+	const returnData = await getColumns.call(this);
+	return returnData.filter((column) => column.value !== columnToMatchOn);
+}