Define DataHub Queries
You can define a database query from your Litmus Add-ins in a structured, sequential way. The process resembles the syntax familiar to queries in dashboard tools like Grafana and executes within an Excel-integrated query.
- Ensure at least one DataHub connection is already created. See Define DataHub Connections for details.
- Confirm that your selected database includes the necessary measurements (tables). See Configure an External DataHub Source to learn more.
- Open a new Excel file with Litmus Excel Add-ins enabled. See Step 4: Verify Litmus Excel Add-in Activation in Excel to learn more.
Click on Manage DataHub Queries.
- The Litmus DataHub Queries window pops up. You can take the following actions from this page:
- Add a New Queries: See Step 2 (Next Step) below for detailed steps.
- Learn more: This Add-in only supports Queries using InfluxDB v1. You can access the InfluxDB Documentation through this link.
Note: Verify the visibility of the Add button, which indicates readiness for query creation. If the Add button isn't visible, check the Define DataHub Connections guide.
Click the Add button to begin the process.
The system will prompt for a query name and connection selection.
- Query Name: The tool auto-generates a default query name that includes the creation date and time. (Optionally) Modify the default name to align with your internal naming standards.
- Connection Name: Choose the appropriate connection from the drop-down menu. See Define DataHub Connections if you don't see any defined connection.
Configure the following fields:
- From: Pick the desired table (from the drop-down menu) for the query.
- Query Statement: It displays only the query that the user configures using all the other tools.
- Time Range, Order By, Limit, SLimit, Select, Where: The system constructs a default query that:
- Applies a mean calculation on the selected field.
- Groups results by time.
- Orders data in ascending order.
- Note: The default time range is set to the last hour.
- If the query syntax is correct, you will see the message "Query is executable." in green at the bottom.
Use the preview icon to display the first 10 rows of query results. The Results for Action Execution window appears.
The preview serves as an initial data check.
Troubleshooting: A lack of data may indicate:
- An incorrect query configuration.
- A combination of conditions that returns no data.
- No data available within the selected time range.
After validating the query setup, click Save to save the query.
When saved, a new Excel sheet with query details is added, and the dashboard updates accordingly.
Note: The query remains functional independently of the DataHub add-in and can be refreshed directly via Excel’s data refresh option.