How to declare the err variable in Go when calling sql.Open if the db variable is global?

Question

go

Here's how to track connection errors in such a situation?

var db *sql.DB

func connectDB() {
    db, _ = sql.Open("mysql", "[email protected]/dbname")
}

If the db variable is not declared in advance, then everything is clear, but how do they do it in this case?

Answer 1

var db *sql.DB

func connectDB() {
    var err error
    db, err = sql.Open("mysql", "[email protected]/dbname")
}

and with processing:

var db *sql.DB

func connectDB() error {
    var err error
    if db, err = sql.Open("mysql", "[email protected]/dbname"); err != nil {
        return err
    }

or like this:

var db *sql.DB

func connectDB() (err error) {
    db, err = sql.Open("mysql", "[email protected]/dbname")
    return
}

Answer 2

She is a link. Reassignment is not a problem.