Add an officially supported query compilation function
Often, when my queries are not accepted by the backend (ProgrammingError) I want to look at the generated SQL and tinker with it, executing it directly on the backend until I figure out what's wrong. Trouble is, when I print the query with str(query), it gives me the non-interpolated version of the query (ie. with the placeholders not filled in). Many people have been asking for a way to get a compiled version of the query, which could be copypasted directly to psql or whatever.
SQLACodegen also requires a method for compiling expressions, given a dialect. I've used an adapted version of this: http://stackoverflow.com/a/5698357/242021 However, the 0.8.3 update broke it. One of my tests is now giving me:
AttributeError: Neither 'Label' object nor 'Comparator' object has an attribute 'table'
That's one more reason why I'm requesting an official compiling method that won't break with micro version updates of SQLAlchemy.