We ended up with a rather convoluted approach. We have a "utility" server that acts as a REST target for ServiceNow. Within that server, we run python scripts than in turn query all our SQL instances and returns a JSON payload back to ServiceNow.

We could have done it with a workflow that would use a PowerShell step (running on a MID server) to return a JSON package. That package could then be process by a Javascript. You could also just use PowerShell to call your ServiceNow instance directly and push the data that way.