GoRel is a port of Arel, a SQL AST manager for Ruby.
I found it quite useful, and I thought it may be useful for people working in Go.
I've got some good support for SELECT, and should be able to add the rest fairly soon. It also only supports MySQL at the moment, but adding Postgresql and others should be fairly easy. If you'd like to use it, install gb, run the tests and have a look at them for syntax.
There's a few failing tests: I'm working on those at the momemnt.
I'd be interested to know how to do this in idiomatic Go, so feel free to leave some feedback, or fork and I'll keep a watch on your work.