Upgraded selectRelated to work like in the current Django version.

src/db/QDjangoMetaModel.cpp

@@ -725,7 +725,7 @@ void QDjangoMetaModel::setForeignKey(QObject *model, const char *name, QObject *
 /*!
     Loads the given properties into a \a model instance.
 */
-void QDjangoMetaModel::load(QObject *model, const QVariantList &properties, int &pos) const
+void QDjangoMetaModel::load(QObject *model, const QVariantList &properties, int &pos, const QStringList &relatedFields) const
 {
     // process local fields
     foreach (const QDjangoMetaField &field, d->localFields)
@@ -736,11 +736,26 @@ void QDjangoMetaModel::load(QObject *model, const QVariantList &properties, int
         return;
     foreach (const QByteArray &fkName, d->foreignFields.keys())
     {
-        QObject *object = model->property(fkName + "_ptr").value<QObject*>();
-        if (object)
+        QString fkS(fkName);
+        if ( relatedFields.contains(fkS) )
         {
-            const QDjangoMetaModel foreignMeta = QDjango::metaModel(d->foreignFields[fkName]);
-            foreignMeta.load(object, properties, pos);
+            QStringList nsl = relatedFields.filter(QRegExp("^" + fkS + "__")).replaceInStrings(QRegExp("^" + fkS + "__"),"");
+            QObject *object = model->property(fkName + "_ptr").value<QObject*>();
+            if (object)
+            {
+                const QDjangoMetaModel foreignMeta = QDjango::metaModel(d->foreignFields[fkName]);
+                foreignMeta.load(object, properties, pos, nsl);
+            }
+        }
+
+        if (relatedFields.isEmpty())
+        {
+            QObject *object = model->property(fkName + "_ptr").value<QObject*>();
+            if (object)
+            {
+                const QDjangoMetaModel foreignMeta = QDjango::metaModel(d->foreignFields[fkName]);
+                foreignMeta.load(object, properties, pos);
+            }
         }
     }
 }

src/db/QDjangoMetaModel.h

@@ -21,6 +21,7 @@
 #include <QMap>
 #include <QSharedDataPointer>
 #include <QVariant>
+#include <QStringList>
 
 #include "QDjango_p.h"
 
@@ -75,7 +76,7 @@ class QDJANGO_DB_EXPORT QDjangoMetaModel
     QStringList createTableSql() const;
     bool dropTable() const;
 
-    void load(QObject *model, const QVariantList &props, int &pos) const;
+    void load(QObject *model, const QVariantList &props, int &pos, const QStringList &relatedFields = QStringList()) const;
     bool remove(QObject *model) const;
     bool save(QObject *model) const;
 

src/db/QDjangoQuerySet.cpp

@@ -99,7 +99,7 @@ QString QDjangoCompiler::databaseColumn(const QString &name)
     return modelRef + QLatin1Char('.') + driver->escapeIdentifier(field.column(), QSqlDriver::FieldName);
 }
 
-QStringList QDjangoCompiler::fieldNames(bool recurse, QDjangoMetaModel *metaModel, const QString &modelPath, bool nullable)
+QStringList QDjangoCompiler::fieldNames(bool recurse, const QStringList *fields, QDjangoMetaModel *metaModel, const QString &modelPath, bool nullable)
 {
     QStringList columns;
     if (!metaModel)
@@ -117,7 +117,17 @@ QStringList QDjangoCompiler::fieldNames(bool recurse, QDjangoMetaModel *metaMode
     foreach (const QByteArray &fkName, metaModel->foreignFields().keys()) {
         QDjangoMetaModel metaForeign = QDjango::metaModel(metaModel->foreignFields()[fkName]);
         bool nullableForeign = metaModel->localField(fkName + QByteArray("_id")).isNullable();
-        columns += fieldNames(recurse, &metaForeign, pathPrefix + QString::fromLatin1(fkName), nullableForeign);
+        QString fkS(fkName);
+        if ( (fields != 0) && (fields->contains(fkS) ) )
+        {
+            QStringList nsl = fields->filter(QRegExp("^" + fkS + "__")).replaceInStrings(QRegExp("^" + fkS + "__"),"");
+            columns += fieldNames(recurse, &nsl, &metaForeign, pathPrefix + QString::fromLatin1(fkName), nullableForeign);
+        }
+
+        if (fields == 0)
+        {
+            columns += fieldNames(recurse, 0, &metaForeign, pathPrefix + QString::fromLatin1(fkName), nullableForeign);
+        }
     }
     return columns;
 }
@@ -335,7 +345,7 @@ bool QDjangoQuerySetPrivate::sqlLoad(QObject *model, int index)
 
     const QDjangoMetaModel metaModel = QDjango::metaModel(m_modelName);
     int pos = 0;
-    metaModel.load(model, properties.at(index), pos);
+    metaModel.load(model, properties.at(index), pos, this->relatedFields);
     return true;
 }
 
@@ -400,7 +410,7 @@ QDjangoQuery QDjangoQuerySetPrivate::insertQuery(const QVariantMap &fields) cons
     foreach (const QString &name, fields.keys()) {
         const QDjangoMetaField field = metaModel.localField(name.toLatin1());
         fieldColumns << db.driver()->escapeIdentifier(field.column(), QSqlDriver::FieldName);
-        fieldHolders << QLatin1String("?");
+        fieldHolders << QString::fromLatin1(":%1").arg(name);
     }
 
     QDjangoQuery query(db);
@@ -423,7 +433,7 @@ QDjangoQuery QDjangoQuerySetPrivate::selectQuery() const
     QDjangoWhere resolvedWhere(whereClause);
     compiler.resolve(resolvedWhere);
 
-    const QStringList columns = compiler.fieldNames(selectRelated);
+    const QStringList columns = compiler.fieldNames(selectRelated, &this->relatedFields);
     const QString where = resolvedWhere.sql(db);
     const QString limit = compiler.orderLimitSql(orderBy, lowMark, highMark);
     QString sql = QLatin1String("SELECT ") + columns.join(QLatin1String(", ")) + QLatin1String(" FROM ") + compiler.fromSql();

src/db/QDjangoQuerySet.h

@@ -296,7 +296,7 @@ template <class T>
     QDjangoQuerySet limit(int pos, int length = -1) const;
     QDjangoQuerySet none() const;
     QDjangoQuerySet orderBy(const QStringList &keys) const;
-    QDjangoQuerySet selectRelated() const;
+    QDjangoQuerySet selectRelated(const QStringList &relatedFields = QStringList()) const;
 
     int count() const;
     QDjangoWhere where() const;
@@ -425,6 +425,7 @@ QDjangoQuerySet<T> QDjangoQuerySet<T>::all() const
     other.d->highMark = d->highMark;
     other.d->orderBy = d->orderBy;
     other.d->selectRelated = d->selectRelated;
+    other.d->relatedFields = d->relatedFields;
     other.d->whereClause = d->whereClause;
     return other;
 }
@@ -577,12 +578,18 @@ bool QDjangoQuerySet<T>::remove()
 /** Returns a QDjangoQuerySet that will automatically "follow" foreign-key
  *  relationships, selecting that additional related-object data when it
  *  executes its query.
+ *
+ *  \param relatedFields If provided it will follow only the listed foreign
+ *  keys. This is handy for very complex DB structures and allows the user
+ *  to limit the amount of retrieved data. If omitted, the basic functionality
+ *  is preserved and the function will traverse all foreign key relationships.
  */
 template <class T>
-QDjangoQuerySet<T> QDjangoQuerySet<T>::selectRelated() const
+QDjangoQuerySet<T> QDjangoQuerySet<T>::selectRelated(const QStringList &relatedFields) const
 {
     QDjangoQuerySet<T> other = all();
     other.d->selectRelated = true;
+    other.d->relatedFields = relatedFields;
     return other;
 }
 

src/db/QDjangoQuerySet_p.h

@@ -61,7 +61,7 @@ class QDJANGO_DB_EXPORT QDjangoCompiler
 public:
     QDjangoCompiler(const char *modelName, const QSqlDatabase &db);
     QString fromSql();
-    QStringList fieldNames(bool recurse, QDjangoMetaModel *metaModel = 0, const QString &modelPath = QString(), bool nullable = false);
+    QStringList fieldNames(bool recurse, const QStringList *fields = 0, QDjangoMetaModel *metaModel = 0, const QString &modelPath = QString(), bool nullable = false);
     QString orderLimitSql(const QStringList &orderBy, int lowMark, int highMark);
     void resolve(QDjangoWhere &where);
 
@@ -110,6 +110,7 @@ class QDJANGO_DB_EXPORT QDjangoQuerySetPrivate
     QStringList orderBy;
     QList<QVariantList> properties;
     bool selectRelated;
+    QStringList relatedFields;
 
 private:
     Q_DISABLE_COPY(QDjangoQuerySetPrivate)