Telegram Bot for Item Multi-Select and Saving to Postgres

This n8n workflow provides a Telegram bot that allows users to select multiple items from a predefined list and then saves these selections to a PostgreSQL database. It's ideal for scenarios requiring user input for multiple choices, such as task assignments, preference settings, or inventory management, all managed through a conversational interface.

What it does

1. Listens for Telegram Messages: The workflow is triggered by incoming messages to a configured Telegram bot.
2. Initial Command Handling: It checks if the incoming message is a /start command.
   • If /start, it sends a welcome message and presents a list of items as inline keyboard buttons for multi-selection.
   • If not /start, it proceeds to process potential item selections.
3. Processes Item Selections:
   • It identifies if the incoming message is a callback query (i.e., a user clicking an inline button).
   • It extracts the selected item and the user's current selections from the callback data.
   • It toggles the selection status of the clicked item (add if not selected, remove if already selected).
   • It reconstructs the inline keyboard with updated checkboxes reflecting the current selections.
   • It updates the Telegram message to reflect the new selection status.
4. Handles "Save" Action:
   • If the user clicks the "Save" button, it extracts the final list of selected items.
   • It formats the selected items into a JSON string.
   • It inserts the user's chat ID and the JSON string of selected items into a PostgreSQL database table.
   • It sends a confirmation message to the user via Telegram.
5. Handles "Cancel" Action:
   • If the user clicks the "Cancel" button, it clears the current selections and sends a cancellation message.

Prerequisites/Requirements

• Telegram Bot: A Telegram bot token obtained from BotFather.
• PostgreSQL Database: Access to a PostgreSQL database with a table configured to store the chat ID and selected items (e.g., a TEXT or JSONB column for items).
• n8n Instance: A running n8n instance to host the workflow.

Setup/Usage

1. Import the Workflow: Import the provided JSON into your n8n instance.
2. Configure Telegram Trigger:
   • Edit the "Telegram Trigger" node.
   • Select or create a new Telegram API credential. You will need your Telegram Bot Token.
   • Ensure the "Update Type" is set to "Message" and "Callback Query" to capture both text messages and button clicks.
3. Configure Telegram Node:
   • Edit all "Telegram" nodes in the workflow.
   • Select the same Telegram API credential used in the trigger.
4. Configure PostgreSQL Node:
   • Edit the "Postgres" node.
   • Select or create a new PostgreSQL credential, providing your database host, port, database name, user, and password.
   • Update the "Table Name" and "Columns" in the "Postgres" node to match your database schema. The workflow expects to insert chat_id and selected_items (as a JSON string).
5. Define Items:
   • The list of selectable items is currently hardcoded within the "Code" node (specifically in the part that generates the inline keyboard). You will need to modify this node to define your desired items.
6. Activate the Workflow: Save and activate the workflow.

Once configured, send a /start command to your Telegram bot to begin interacting with it.