Put your functions/procs into files. Check them into git. Use Liquibase (or flyway, etc.) to wrap the files as migrations with rerun-on-change. Deploy by running the Liquibase cli, or directly from your app on startup.

For testing, write some tests and run them. I used ut_plsql when I was working with Oracle.

For debugging, a log table is easy. Have a log() function that inserts into a log table inside a tx-new. You can also use an interactive debugger. Postgres, Oracle, and MS all provide gui debuggers. They aren't as advanced as IntelliJ, but they let you set breakpoints, inspect variables, etc.