The easiest way I have found to avoid this error is simply not to pass the `db` around so much. Every data access function (even seemingly trivial ones) should

The easiest way I have found to avoid this error is simply not to pass the `db` around so much. Every data access function (even seemingly trivial ones) should take a `Tx` instead. This also makes your code "composition-ready" if necessary later. IMO the standard library should provide something that wraps a `Tx` and a `Context` together, as usually I want every statement issued from a transaction bounded in lifetime by the same one I provided to `BeginTx`. This would provide even more incentive to pass around `Tx`s rather than `DB`s, since those functions also often need a context anyway.