I'm trying to write a mySQL statement that joins across tables within my App

I'm trying to write a mySQL statement that joins across tables within my Appian database.

First off, is that possible to write a statement that will query across my different tables?
If so, do I need to put the schema at the beginning? When attempting to write the query it is actually unable to identify that table (even just for a basic query) so I trust I'm not writing the correct syntax. Where do I go to write a query across multiple tables as I assume coming to the SQL tab within a table would be specific to that table?

Appreciate the help!...

OriginalPostID-86116

OriginalPostID-86116