start QAD::SQL library

QAD::SQLQuery wrapper to minimize code of QSqlQuery usage

libs/sql/sql_query.h

@@ -0,0 +1,63 @@
+/*
+    QAD - Qt ADvanced
+
+	Ivan Pelipenko peri4ko@yandex.ru
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef sql_query_H
+#define sql_query_H
+
+#include "qad_sql_export.h"
+
+#include <QMap>
+#include <QSqlError>
+#include <QSqlQuery>
+#include <QVariant>
+
+
+namespace QAD {
+
+class QAD_SQL_EXPORT SQLQuery {
+public:
+	SQLQuery(QString query_ = QString(), QVariantMap params = QVariantMap(), QSqlDatabase db = QSqlDatabase());
+	~SQLQuery();
+
+	struct Result {
+		bool ok           = false;
+		QVariant insertId = -1;
+	};
+
+	typedef std::function<void(QString, QVariantMap, QSqlError)> HandlerFail;
+
+	QSqlQuery & query() { return q; }
+
+	static Result exec(QString query_, QVariantMap params = QVariantMap(), QSqlDatabase db = QSqlDatabase());
+
+	static void setFailHandler(HandlerFail h);
+
+protected:
+	QSqlQuery q;
+
+private:
+	struct Singleton {
+		static Singleton * instance();
+		HandlerFail fail_handler;
+	};
+};
+
+} // namespace QAD
+
+#endif