func (c *conn) Exec(query string, args []driver.Value) (driver.Result, error) {
	panic("deprecated")
}
func (c *conn) Exec(query string, args []driver.Value) (driver.Result, error) {
	panic("deprecated")
}
// Exec implements the database/sql/driver/Execer interface.
// delete after go 1.9 compatibility is given up.