sqlconversationmodel.cpp Example File | Qt Quick Controls 5.12.8

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# sqlconversationmodel.cpp Example File

chattutorial/chapter5-styling/sqlconversationmodel.cpp

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     #include "sqlconversationmodel.h"

     #include <QDateTime>
     #include <QDebug>
     #include <QSqlError>
     #include <QSqlRecord>
     #include <QSqlQuery>

     static const char *conversationsTableName = "Conversations";

     static void createTable()
     {
         if (QSqlDatabase::database().tables().contains(conversationsTableName)) {
             // The table already exists; we don't need to do anything.
             return;
         }

         QSqlQuery query;
         if (!query.exec(
             "CREATE TABLE IF NOT EXISTS 'Conversations' ("
             "'author' TEXT NOT NULL,"
             "'recipient' TEXT NOT NULL,"
             "'timestamp' TEXT NOT NULL,"
             "'message' TEXT NOT NULL,"
             "FOREIGN KEY('author') REFERENCES Contacts ( name ),"
             "FOREIGN KEY('recipient') REFERENCES Contacts ( name )"
             ")")) {
             qFatal("Failed to query database: %s", qPrintable(query.lastError().text()));
         }

         query.exec("INSERT INTO Conversations VALUES('Me', 'Ernest Hemingway', '2016-01-07T14:36:06', 'Hello!')");
         query.exec("INSERT INTO Conversations VALUES('Ernest Hemingway', 'Me', '2016-01-07T14:36:16', 'Good afternoon.')");
         query.exec("INSERT INTO Conversations VALUES('Me', 'Albert Einstein', '2016-01-01T11:24:53', 'Hi!')");
         query.exec("INSERT INTO Conversations VALUES('Albert Einstein', 'Me', '2016-01-07T14:36:16', 'Good morning.')");
         query.exec("INSERT INTO Conversations VALUES('Hans Gude', 'Me', '2015-11-20T06:30:02', 'God morgen. Har du fått mitt maleri?')");
         query.exec("INSERT INTO Conversations VALUES('Me', 'Hans Gude', '2015-11-20T08:21:03', 'God morgen, Hans. Ja, det er veldig fint. Tusen takk! "
                    "Hvor mange timer har du brukt på den?')");
     }

     SqlConversationModel::SqlConversationModel(QObject *parent) :
         QSqlTableModel(parent)
     {
         createTable();
         setTable(conversationsTableName);
         setSort(2, Qt::DescendingOrder);
         // Ensures that the model is sorted correctly after submitting a new row.
         setEditStrategy(QSqlTableModel::OnManualSubmit);
     }

     QString SqlConversationModel::recipient() const
     {
         return m_recipient;
     }

     void SqlConversationModel::setRecipient(const QString &recipient)
     {
         if (recipient == m_recipient)
             return;

         m_recipient = recipient;

         const QString filterString = QString::fromLatin1(
             "(recipient = '%1' AND author = 'Me') OR (recipient = 'Me' AND author='%1')").arg(m_recipient);
         setFilter(filterString);
         select();

         emit recipientChanged();
     }

     QVariant SqlConversationModel::data(const QModelIndex &index, int role) const
     {
         if (role < Qt::UserRole)
             return QSqlTableModel::data(index, role);

         const QSqlRecord sqlRecord = record(index.row());
         return sqlRecord.value(role - Qt::UserRole);
     }

     QHash<int, QByteArray> SqlConversationModel::roleNames() const
     {
         QHash<int, QByteArray> names;
         names[Qt::UserRole] = "author";
         names[Qt::UserRole + 1] = "recipient";
         names[Qt::UserRole + 2] = "timestamp";
         names[Qt::UserRole + 3] = "message";
         return names;
     }

     void SqlConversationModel::sendMessage(const QString &recipient, const QString &message)
     {
         const QString timestamp = QDateTime::currentDateTime().toString(Qt::ISODate);

         QSqlRecord newRecord = record();
         newRecord.setValue("author", "Me");
         newRecord.setValue("recipient", recipient);
         newRecord.setValue("timestamp", timestamp);
         newRecord.setValue("message", message);
         if (!insertRecord(rowCount(), newRecord)) {
             qWarning() << "Failed to send message:" << lastError().text();
             return;
         }

         submitAll();
     }