Change boundValues() to return a QVariantList

This enables the order of boundValues to be consistent as with a QMap
it could have been reordered which can be a problem for positional
bindings.

[ChangeLog][QtSQL] Changed signature of QSqlQuery::boundValues() to
return a QVariantList

Fixes: QTBUG-51609
Change-Id: I1c80fa8522fa7352723420b6fc9ec466406315fb
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

4 files changed, 83 insertions, 32 deletions

diff --git a/src/sql/doc/snippets/sqldatabase/sqldatabase.cpp b/src/sql/doc/snippets/sqldatabase/sqldatabase.cpp
index c28e750b16..001e2ba3b2 100644
--- a/src/sql/doc/snippets/sqldatabase/sqldatabase.cpp
+++ b/src/sql/doc/snippets/sqldatabase/sqldatabase.cpp
@@ -50,7 +50,6 @@
 
 #include <QCoreApplication>
 #include <QtSql>
-#include <QMap>
 #include <iostream>
 
 using namespace std;
@@ -202,23 +201,12 @@ void QSqlQuery_snippets()
     QSqlQuery query;
 
     {
-    // examine with named binding
+    // examine with named or positional binding
 //! [14]
-    QMap<QString, QVariant> sqlIterator(query.boundValues());
-    for (auto i = sqlIterator.begin(); i != sqlIterator.end(); ++i) {
-        cout << i.key().toUtf8().data() << ": "
-             << i.value().toString().toUtf8().data() << "\n";
-    }
-//! [14]
-    }
-
-    {
-    // examine with positional binding
-//! [15]
-    QList<QVariant> list = query.boundValues().values();
+    QVariantList list = query.boundValues();
     for (int i = 0; i < list.size(); ++i)
         cout << i << ": " << list.at(i).toString().toUtf8().data() << "\n";
-//! [15]
+//! [14]
     }
 }
 
diff --git a/src/sql/doc/src/qt6-changes.qdoc b/src/sql/doc/src/qt6-changes.qdoc
new file mode 100644
index 0000000000..4bde13e0ed
--- /dev/null
+++ b/src/sql/doc/src/qt6-changes.qdoc
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \page qtsql-changes-qt6.html
+    \title Porting to Qt 6 - Qt Sql
+
+    Qt 6 is a result of the conscious effort to make the framework more
+    efficient and easy to use.
+
+    We try to maintain binary and source compatibility for all the public
+    APIs in each release. But some changes were inevitable in an effort to
+    make Qt a better framework.
+
+    In this topic we summarize those changes in Qt Sql, and provide guidance
+    to handle them.
+
+    \section1 QSqlQuery
+
+    \section2 boundValues() Signature
+
+    The return type for boundValues() has been changed from QMap<QString, QVariant>
+    to a QVariantList. The order can be relied upon so it will be in the order of the
+    binding in the prepared query. Change code like the following:
+
+    \code
+    QMap<QString, QVariant> values = boundValues();
+    int id = values[":id"].value().toInt();
+    \endcode
+
+    \code
+    QList<QVariant> values = boundValues().values();
+    int id = values.at(0).toInt();
+    \endcode
+
+    to:
+
+    \code
+    QList<QVariant> values = boundValues().values();
+    int id = values.at(0).toInt();
+    \endcode
+*/
diff --git a/src/sql/kernel/qsqlquery.cpp b/src/sql/kernel/qsqlquery.cpp
index 98e65b019c..1e848f4168 100644
--- a/src/sql/kernel/qsqlquery.cpp
+++ b/src/sql/kernel/qsqlquery.cpp
@@ -180,7 +180,7 @@ QSqlQueryPrivate::~QSqlQueryPrivate()
     them in the same query.
 
     You can retrieve the values of all the fields in a single variable
-    (a map) using boundValues().
+    using boundValues().
 
     \note Not all SQL operations support binding values. Refer to your database
     system's documentation to check their availability.
@@ -1144,27 +1144,24 @@ QVariant QSqlQuery::boundValue(int pos) const
 }
 
 /*!
-  Returns a map of the bound values.
+  \since 6.0
 
-  With named binding, the bound values can be examined in the
-  following ways:
+  Returns a list of bound values.
 
-  \snippet sqldatabase/sqldatabase.cpp 14
+  The order of the list is in binding order, irrespective of whether
+  named or positional binding is used.
 
-  With positional binding, the code becomes:
+  The bound values can be examined in the following way:
 
-  \snippet sqldatabase/sqldatabase.cpp 15
+  \snippet sqldatabase/sqldatabase.cpp 14
 
   \sa boundValue(), bindValue(), addBindValue()
 */
-QMap<QString,QVariant> QSqlQuery::boundValues() const
-{
-    QMap<QString,QVariant> map;
 
-    const QVector<QVariant> values(d->sqlResult->boundValues());
-    for (int i = 0; i < values.count(); ++i)
-        map[d->sqlResult->boundValueName(i)] = values.at(i);
-    return map;
+QVariantList QSqlQuery::boundValues() const
+{
+    const QVariantList values(d->sqlResult->boundValues());
+    return values;
 }
 
 /*!
diff --git a/src/sql/kernel/qsqlquery.h b/src/sql/kernel/qsqlquery.h
index 3be04c492c..b270441273 100644
--- a/src/sql/kernel/qsqlquery.h
+++ b/src/sql/kernel/qsqlquery.h
@@ -43,18 +43,18 @@
 #include <QtSql/qtsqlglobal.h>
 #include <QtSql/qsqldatabase.h>
 #include <QtCore/qstring.h>
+#include <QtCore/qvariant.h>
 
 QT_BEGIN_NAMESPACE
 
 
-class QVariant;
 class QSqlDriver;
 class QSqlError;
 class QSqlResult;
 class QSqlRecord;
-template <class Key, class T> class QMap;
 class QSqlQueryPrivate;
 
+
 class Q_SQL_EXPORT QSqlQuery
 {
 public:
@@ -107,7 +107,7 @@ public:
     void addBindValue(const QVariant& val, QSql::ParamType type = QSql::In);
     QVariant boundValue(const QString& placeholder) const;
     QVariant boundValue(int pos) const;
-    QMap<QString, QVariant> boundValues() const;
+    QVariantList boundValues() const;
     QString executedQuery() const;
     QVariant lastInsertId() const;
     void finish();