Add sum feature (#83)

* Fix possible refering to unallocated memory by using QSharedPointer in
Query::toList

* - Implemented sum field feature
- Fixed SingleField typo
- Added test for sum, and count field feature
- Fixed test case for average field feature

src/generators/sqlgeneratorbase.cpp

@@ -512,7 +512,10 @@ QString SqlGeneratorBase::agregateText(const AgregateType &t,
     case Count:
         return "COUNT(" + arg + ")";
 
-    case SignleField:
+    case Sum:
+        return "SUM(" + arg + ")";
+
+    case SingleField:
         return arg;
     }
     return QString(); // never reach

src/generators/sqlgeneratorbase_p.h

@@ -61,18 +61,19 @@ public:
         Min,
         Max,
         Average,
-        SignleField
+        SingleField,
+        Sum
     };
 
     explicit SqlGeneratorBase(Database *parent);
     virtual ~SqlGeneratorBase() = default;
 
     virtual bool supportPrimaryKey(const QMetaType::Type &type) {
-        Q_UNUSED(type);
+        Q_UNUSED(type)
         return true;
     }
     virtual bool supportAutoIncrement(const QMetaType::Type &type) {
-        Q_UNUSED(type);
+        Q_UNUSED(type)
         return true;
     }
 

src/query.h

@@ -92,6 +92,7 @@ public:
     int count();
     QVariant max(const FieldPhrase<int> &f);
     QVariant min(const FieldPhrase<int> &f);
+    QVariant sum(const FieldPhrase<int> &f);
     QVariant average(const FieldPhrase<int> &f);
 
     QVariant insert(const AssignmentPhraseList &p);
@@ -119,7 +120,7 @@ Q_OUTOFLINE_TEMPLATE QList<O> Query<T>::select(const std::function<O (const QSql
     d->joins.prepend(d->tableName);
     d->sql = d->database->sqlGenertor()->selectCommand(
                 d->tableName,
-                SqlGeneratorBase::SignleField, "*",
+                SqlGeneratorBase::SingleField, "*",
                 d->wherePhrase,
                 d->relations,
                 d->skip, d->take);
@@ -350,7 +351,7 @@ Q_OUTOFLINE_TEMPLATE QList<F> Query<T>::select(const FieldPhrase<F> f)
     d->joins.prepend(d->tableName);
     d->sql = d->database->sqlGenertor()->selectCommand(
                 d->tableName,
-                SqlGeneratorBase::SignleField, f.data->toString(),
+                SqlGeneratorBase::SingleField, f.data->toString(),
                 d->wherePhrase,
                 d->relations,
                 d->skip, d->take);
@@ -435,6 +436,24 @@ Q_OUTOFLINE_TEMPLATE QVariant Query<T>::min(const FieldPhrase<int> &f)
     return 0;
 }
 
+template <class T>
+Q_OUTOFLINE_TEMPLATE QVariant Query<T>::sum(const FieldPhrase<int> &f)
+{
+    Q_D(Query);
+
+    d->joins.prepend(d->tableName);
+    d->sql = d->database->sqlGenertor()->selectCommand(
+                d->tableName,
+                SqlGeneratorBase::Sum, f.data->toString(),
+                d->wherePhrase,
+                d->relations);
+    QSqlQuery q = d->database->exec(d->sql);
+
+    if (q.next())
+        return q.value(0).toInt();
+    return 0;
+}
+
 template <class T>
 Q_OUTOFLINE_TEMPLATE QVariant Query<T>::average(const FieldPhrase<int> &f)
 {

test/tst_basic/tst_basic.cpp

@@ -170,11 +170,23 @@ void BasicTest::selectPosts()
 
 void BasicTest::selectScoreAverage()
 {
-    auto a = db.scores()->query()
+    auto avg = db.scores()->query()
             ->join<Post>()
             ->setWhere(Post::idField() == 1)
             ->average(Score::scoreField());
-    qDebug() << a;
+    QCOMPARE(avg, 2);
+}
+
+void BasicTest::selectScoreSum()
+{
+    auto sum = db.scores()->query()->sum(Score::scoreField());
+    QCOMPARE(sum, 20);
+}
+
+void BasicTest::selectScoreCount()
+{
+    auto count = db.scores()->query()->count();
+    QCOMPARE(count, 10);
 }
 
 void BasicTest::selectFirst()

test/tst_basic/tst_basic.h

@@ -31,6 +31,8 @@ private slots:
     void join();
     void selectPosts();
     void selectScoreAverage();
+    void selectScoreSum();
+    void selectScoreCount();
     void selectFirst();
     void selectPostsWithoutTitle();
     void selectPostIds();