Create a QuestDB Table and Insert Data

Overview

This workflow automates the process of creating a new table in QuestDB and inserting a single row of data into it. It is triggered manually, making it ideal for testing database operations or bootstrapping a schema before integrating with other automated pipelines. The workflow demonstrates how to execute raw SQL statements and then perform an insert using n8n's QuestDB node.

Workflow Steps

1. On clicking 'execute' (Manual Trigger) — No auth required. This node starts the workflow when you click the "Execute Workflow" button in the n8n editor. It is useful for testing and one-off operations.

2. QuestDB (QuestDB node, operation: executeQuery) — Database credentials required (host, port, username, password). This node runs the SQL statement CREATE TABLE test (id INT, name STRING); to create a new table named test with two columns: an integer id and a string name. The alwaysOutputData option is enabled, so the node always passes data downstream even if the query returns no rows.

3. Set (Set node) — No auth required. This node prepares the data to be inserted. It sets two fields:

   • id (number) — The value is left empty in the configuration (likely intended to be filled dynamically or from previous data).
   • name (string) — Set to the static value "Tanay". The output of this node becomes the input for the next QuestDB node.

4. QuestDB1 (QuestDB node, operation: insert) — Same database credentials as the first QuestDB node. This node inserts the data from the Set node into the test table. The table parameter is set to "test" and the columns parameter is "id, name". The actual values come from the incoming data (the id and name fields set by the previous node).

Setup Instructions

1. QuestDB instance — You need a running QuestDB server. You can install it locally or use a cloud instance. Obtain the host, port (default 8812 for PostgreSQL wire protocol), username, and password.
2. n8n credentials — In n8n, create a new QuestDB credential. Enter the host, port, database name (if any), username, and password. The same credential will be used by both QuestDB nodes.
3. Manual trigger — No additional setup required. Just click the "Execute Workflow" button in the editor to run the workflow.

Use Cases & Variations

• Schema initialization — Use this workflow as a template to create tables before running data ingestion pipelines.
• Dynamic data insertion — Replace the Set node with an HTTP Request node (e.g., from a webhook or API) to insert data from external sources.
• Batch inserts — Modify the workflow to loop over an array of records and insert multiple rows using the QuestDB node's insert operation.
• Error handling — Add an error trigger or conditional logic to handle cases where the table already exists (e.g., use CREATE TABLE IF NOT EXISTS).
• Scheduled execution — Replace the manual trigger with a Schedule Trigger to run the workflow at regular intervals (e.g., daily data refresh).

{
  "id": "161",
  "name": "Create a table and insert data into it",
  "nodes": [
    {
      "name": "On clicking 'execute'",
      "type": "n8n-nodes-base.manualTrigger",
      "position": [
        440,
        460
      ],
      "parameters": {},
      "typeVersion": 1
    },
    {
      "name": "Set",
      "type": "n8n-nodes-base.set",
      "position": [
        840,
        460
      ],
      "parameters": {
        "values": {
          "number": [
            {
              "name": "id"
            }
          ],
          "string": [
            {
              "name": "name",
              "value": "Tanay"
            }
          ]
        },
        "options": {}
      },
      "typeVersion": 1
    },
    {
      "name": "QuestDB",
      "type": "n8n-nodes-base.questDb",
      "position": [
        640,
        460
      ],
      "parameters": {
        "query": "CREATE TABLE test (id INT, name STRING);",
        "operation": "executeQuery"
      },
// ... truncated (copy to see full JSON)