iFixit/PopSQL — pull request #7 by danielbeardsley (2014-10-11 00:00:55+00:00)
Title: Allow QueryGenerator instances to be used as args

So you can build sub expressions or sub queries:

$q = new QueryGenerator()->useOr()->where("x")->where("y")
$b = new QueryGenerator()->where($q)->where("z");

$b->build() == ["WHERE ((x) OR (y)) AND (z)",[]];

It's also useful if you just want to create a part of a query for use
elsewhere.

new QueryGenerator()->where("z")->build(true) == ["(z)", []];