as Boris said I'm, trying to answer your question. I'm not 100% sure if your question is about writing to Azure SQL or how to manage many RevPis so I try to answer both.
If you want to send data from the RevPi to a Azure SQL Server (or any other Azure data storage like CosmosDB) you have different options. Typical solutions are to use Azure IoT Hub (with IoT Edge and/or MQTT) or a custom web app with a REST interface. This depends very much on the type of installation, firewall/networks and how the overall structure of the project looks like. We use all of the solutions mentioned depending on the project.
Managing multiple RevPis is a little different. The Raspberry Pi platform is supported by Azure IoT Edge so you can use this right away. However, in many projects we work on direct management of RevPis from Azure is not allowed by network security. For those environments or if Azure shall not be used we have two software tools: erMON (Monitoring of RevPis) and erPLOY (Deploying software to RevPis). Both are short explained on https://www.erminas.de/erminas-produkte/
(German only until end of month, then also in English). This way you do not have everything Azure gives you but you can manage and roll-out software, as well as see hardware and software status and historical measurements of your Pis. Also, this can run on-premise.
If you have any further questions please answer to this post or send me a mail.