What version of Go are you using (go version)?

Go 1.9

What did you expect to see?

Documentation about Context propagation for the new database context methods. For example, it isn't clear what happens in the following cases:

• Does DB.BeginTx result in a Tx that has a context, or is the context only applied to the creation of the Tx?
• Does DB.PrepareContext result in a Stmt that uses the passed in context? Phrased differently: does calling stmt.Exec() use the context passed to DB.PrepareContext ?
• Similar to the above question, does Stmt.QueryContext use the context that was used to create it?
• Does Tx.Prepare use the context that was used to create it? (

Reading the code clarifies that context is usually not passed around, but this isn't obvious from the docs. Furthermore, this does not make it clear if this is an implementation detail, or a part of the API.
Ideally, The database docs could include something along the lines of:

func (s *Stmt) Exec(args ... interface{}) (Result, error)

This is equivalent to

func (s *Stmt) ExecContext(context.Background(), args ...) (Result, error)