Changeset c790268 for src/orm/ormrecord.h

Timestamp:

01/17/10 17:22:03 (12 years ago)

Author:

pavelpa <pavelpa@…>

Branches:

master, qt5

Children:

6f39595

Parents:

680a4da

Message:

implemented JOINing two tables

• modified 'ormrecord' to support JOINing two tables
• modified 'event' accordingly, since its items/columns are splitted into two separate tables

File:

• src/orm/ormrecord.h (modified) (5 diffs)

src/orm/ormrecord.h

@@ -10 +10 @@
 #include <QDebug>
 
+// INFO:
+// all record items/columns may be defined in one table (1.), or
+// they can be splitted in two separate tables (2.) (eg. for FTS support)
+// 1.) you have to define "static QString const sTableName"
+// 2.) you have to define two table names:
+//     "static QString const sTable1Name"
+//     "static QString const sTable2Name"
+// and since all record items/columns are handled by one QSqlRecord,
+// you have to also define number of columns that belongs to table 1 (1.), and table 2 (2.)
+// 1.) "static int const sTable1ColCount"
+// 2.) "static int const sTable2ColCount"
+// there are also defined auxiliary methods for 1-Table/2-Tables approach, see bellow
+
 class OrmException
 {
@@ -44 +57 @@
 
     // auxiliary methods
+    static QSqlRecord toRecord(const QList<QSqlField> & columnList);
+    // all record items/columns are in one table
     static QString columnsForSelect(const QString& prefix = QString());
     static QString selectQuery();
     static QString updateQuery();
-    static QSqlRecord toRecord(const QList<QSqlField> & columnList);
+    // record items/columns are stored in two tables
+    static QString columnsForSelectJoin2T(); // for joining two tables
+    static QString selectQueryJoin2T(const QString &key); // for joining two tables
 
     static QVariant convertToC(QVariant value, QVariant::Type colType);
@@ -150 +167 @@
 
 template <typename T>
+QString OrmRecord<T>::columnsForSelectJoin2T()
+{
+    Q_ASSERT((T::sTable1ColCount+T::sTable2ColCount) == T::sColumns.count());
+
+    QStringList prefixedColumns;
+    for (int i=0; i<T::sTable1ColCount; i++)
+    {
+        prefixedColumns.append(QString("%1.%2").arg(T::sTable1Name, T::sColumns.field(i).name()));
+    }
+    for (int j=0; j<T::sTable2ColCount; j++)
+    {
+        prefixedColumns.append(QString("%1.%2").arg(T::sTable2Name, T::sColumns.field(T::sTable1ColCount+j).name()));
+    }
+    return prefixedColumns.join(",");
+}
+
+template <typename T>
 QString OrmRecord<T>::selectQuery()
 {
@@ -156 +190 @@
 
 template <typename T>
+QString OrmRecord<T>::selectQueryJoin2T(const QString &key)
+{
+    return QString("SELECT %1 FROM %2 INNER JOIN %3 ON %4.%5 = %6.%7 ").arg(
+            columnsForSelectJoin2T(),
+            T::sTable1Name,
+            T::sTable2Name,
+            T::sTable1Name,
+            key,
+            T::sTable2Name,
+            key);
+}
+
+template <typename T>
 QString OrmRecord<T>::updateQuery()
 {
-    return QString("UPDATE %1 ").arg(T::sTableName);
+    return QString("UPDATE %1 ").arg(T::sTable1Name);
 }
 
@@ -198 +245 @@
 
 #endif // ORMRECORD_H
+