Hi Lloyd,
The database connection mechanism is completely different in n-tier Web server architecture, such as PowerServer. You have to make some code changes and rethink how things will work in n-tier environment. Here is brief summary how the architecture is different: https://docs.appeon.com/ps2022/Comparing_between_cs_app_and_installable_cloud_app.html
As Andreas pointed out, each of the databases you want to connect to need to be defined in the database configuration section of the Web API tab in the project object. It is very important the username and password you provide has full rights to the database so that the compiler can fully access all relevant tables to generate the correct SQL.
Once you have configured all the database connections your app would possibly need during runtime, then you will need to tell the client app which of the PowerServer database connections you want to use. You do that by dynamically setting the "CacheName" property of the DBParm. Here is some information about that: https://docs.appeon.com/ps2022/Dynamically_mapping_transaction_object_with_cache.html
By default, PowerServer will do a shared connection always using the username/password you specified in the configuration dialog. If you want each user to use their own username/password to connect to the database, then you need to check the box "Allow dynamic connection..."
Last thing to note is that for SQL Anywhere specifically, it uses ODBC rather than a native driver. So on the server (not each client app machine) the appropriate DSN must exist. If the server is 64-bit OS then you need to configure 64-bit DSN (not 32-bit). PowerServer by default tries to run in the highest bitness of the OS unless you explicitly compile the Web APIs for 32-bit.
Best regards,
Armeen
