Optimize Song::InitFromQuery

Use `QSqlQuery::value(int)` or `QSqlRecord::value(int)` instead of `QSqlQuery::value(QString)`.
Make `SqlRow` use `QSqlRecord` directly instead iterating over all columns.

src/utilities/sqlhelper.h

@@ -0,0 +1,114 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2024, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef SQLHELPER_H
+#define SQLHELPER_H
+
+#include <QVariant>
+#include <QString>
+#include <QUrl>
+
+class SqlHelper {
+ public:
+  template <typename T>
+  static QString ValueToString(const T &q, const int n);
+
+  template <typename T>
+  static QUrl ValueToUrl(const T &q, const int n);
+
+  template <typename T>
+  static int ValueToInt(const T &q, const int n);
+
+  template <typename T>
+  static uint ValueToUInt(const T &q, const int n);
+
+  template <typename T>
+  static qint64 ValueToLongLong(const T &q, const int n);
+
+  template <typename T>
+  static float ValueToFloat(const T &q, const int n);
+
+  template <typename T>
+  static bool ValueToBool(const T &q, const int n);
+};
+
+template <typename T>
+QString SqlHelper::ValueToString(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return q.value(n).isNull() ? QString() : q.value(n).toString();
+
+}
+
+template <typename T>
+QUrl SqlHelper::ValueToUrl(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return q.value(n).isNull() ? QUrl() : QUrl(q.value(n).toString());
+
+}
+
+template <typename T>
+int SqlHelper::ValueToInt(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return q.value(n).isNull() ? -1 : q.value(n).toInt();
+
+}
+
+template <typename T>
+uint SqlHelper::ValueToUInt(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return q.value(n).isNull() || q.value(n).toInt() < 0 ? 0 : q.value(n).toInt();
+
+}
+
+template <typename T>
+qint64 SqlHelper::ValueToLongLong(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return q.value(n).isNull() ? -1 : q.value(n).toLongLong();
+
+}
+
+template <typename T>
+float SqlHelper::ValueToFloat(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return q.value(n).isNull() ? -1.0F : q.value(n).toFloat();
+
+}
+
+template <typename T>
+bool SqlHelper::ValueToBool(const T &q, const int n) {
+
+  Q_ASSERT(n < q.count());
+
+  return !q.value(n).isNull() && q.value(n).toInt() == 1;
+
+}
+
+#endif  // SQLHELPER_H