Go: Open two SQLite connections, one for read-write-create and the other for read only

sqlite_rwc_ro.go

// https://github.com/mattn/go-sqlite3/issues/1022#issuecomment-1067353980
func newSqlDb(name string) (*sql.DB, *sql.DB, error) {
	u := url.URL{
		Scheme: "file",
		Opaque: name,
	}
	q := make(url.Values)
	q.Set("mode", "rwc")
	q.Set("_foreign_keys", "true")
	q.Set("_journal_mode", "WAL")
	q.Set("_synchronous", "NORMAL")
	q.Set("_txlock", "immediate")
	u.RawQuery = q.Encode()
	rwc, err := sql.Open("sqlite3", u.String())
	if err != nil {
		return nil, nil, err
	}
	rwc.SetMaxOpenConns(1)
	q = make(url.Values)
	q.Set("mode", "ro")
	u.RawQuery = q.Encode()
	ro, err := sql.Open("sqlite3", u.String())
	if err != nil {
		return nil, nil, err
	}
	return rwc, ro, nil
}