AQL Tabular Data
When requesting points of data (ie. live values or history), you can also request tables of data instead of individual raw channels.
There are a few advantages of data tables if you're using data for analytics…
Data For Every Index
In tables, you have values for every channel for every time, unless a sensor was offline or data was unavailable.
This helps address issues when different data points have different sample times.
Analogue values are interpolated and discrete data values are backfilled and forward-filled to ensure that your data table is ready for use for machine learning, charting, replay or other analytic uses.
A Range of Output Formats
While the AQL language always returns data as JSON, you have the option of asking for several different data formats when requesting tables.
This helps get data directly into a range of products (such as Excel) without needing to parse or re-interpret the data.
Endpoint
The AQL table endpoint is at…
<ardiserver>/aql/api/table?query=<query>&format=<format>
By default, the format used is CSV, but it can be overridden with the following options…
| Name | Meaning |
|---|---|
| CSV | Comma-Delimited Text |
| HTML | Web-Based Table |
| JSON | Javascript Object Notation + Metadata |