Thanks for this reply. I thought that was the problem, however I don't know how to associate the script with the template. I can't find anywhere in the documentation that tells me how to do that.

I am trying a simple mysql query. The database is mysql running in a docker container in the same network as jsreports which is running in a docker container as well.

The problem is, I'm not getting any data. I don't know if the connection has failed or not?
I have tried similar code in a straight node.js program and it works fine. So I think my database connection should be OK, but I'm not sure. How can I tell? Incidentally I have tried an ip address as well as localhost, no difference.

The script for the data load is as follows:

const mysql = require('mysql');
// import { connect,Request } from 'mysql';
const config = {
    "user": "some user",
    "password": "some password",
    "server": "localhost",
    "database": "property"
}
async function beforeRender (req, res) {
    await mysql.connect(config);
    const sqlReq = new mysql.Request();
    const queryResult = await sqlReq.query(
        'select Address1, Postcode, DatePurchased from PropertyTable');
    Object.assign(req.data, {properties: queryResult.recordset }); 

}

And the template has the following simple code:

<h1>Property List</h1>
<Style>
    .mycol {
        width:20%;
        padding:5px;
        background-color:pink;
    }
</Style>
<table>
    <tr>
        <td class='mycol'>Name</td>
        <td class='mycol'>Postcode</td>
        <td class='mycol'>Purchase Date</td>
    </tr>
    {{#each properties}}
     <tr>
        <td class='mycol'>{{Address1}}</td>
        <td class='mycol'>{{Postcode}}</td>
        <td class='mycol'>{{PurchaseDate}}</td>
    </tr>
    {{/each}}
</table>

Here is the profile output.

nfo
+0
Render request 27 queued for execution and waiting for available worker
info
+21
Starting rendering request 27 (user: null)
info
+0
Rendering template { name: property, recipe: chrome-pdf, engine: handlebars, preview: true }
debug
+0
Data item not defined for this template.
debug
+2
Base url not specified, skipping its injection.
debug
+5
Rendering engine handlebars
debug
+61
Executing recipe chrome-pdf
debug
+2
Converting with chrome HeadlessChrome/105.0.5195.125 using chrome-pool strategy
debug
+104
Page request: GET (document) file:///tmp/jsreport/autocleanup/4cc35691-a7f8-4d89-bb32-9a9319a5b7b1-chrome-pdf.html
debug
+42
Page request finished: GET (document) 200 file:///tmp/jsreport/autocleanup/4cc35691-a7f8-4d89-bb32-9a9319a5b7b1-chrome-pdf.html
debug
+8
Running chrome with params {"printBackground":true,"timeout":59909,"margin":{}}
debug
+29
Skipping storing report.
info
+0
Rendering request 27 finished in 275 ms