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QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");

db.setDatabaseName("mudmania.db");
// set Username, Pasword, Hostname alles auch schon probiert.

if (! db.open()) {
    QMessageBox::critical(0, qApp->tr("Cannot open database"),
      qApp->tr("Unable to establish a database connection.\n"
               "MUDmania needs SQLite support, but the database\n"
               "plugin of your Qt is not available.\n\n"
               "Click Cancel to exit."), QMessageBox::Cancel, QMessageBox::NoButton);
}

if (db.isOpenError()) {
	QMessageBox::information(0, "MUDmania DB error 1", db.lastError().text());
}

if (! db.isValid()) {
	QMessageBox::information(0, "MUDmania DB", "error 2");
}

QSqlQuery query("select * from worlds");

// AUch schon so probiert:
//QSqlQuery query("select * from worlds", db);

if (! db.isOpen()) {
    QMessageBox::information(this, "mm", "open err");
}

  if (! query.exec()) {
    QMessageBox::information(this, "mm", "exec");
  }

  if (! query.isActive()) {
    QMessageBox::information(this, "mm", "not active");
  }

  if (! query.isValid()) {
    //QMessageBox::information(this, "mm", "not valid");
  }

// Hier kommt ein Leerstring raus !!!
QMessageBox::information(this, "mm tables", db.tables().join(" "));

// Und hier gibt's eine -1 zurück. War nicht anders zu erwarten...
QMessageBox::information(this, "mm size", QString::number(query.size()));

  int i = query.record().indexOf("name");
  while (query.next()) {
    QString str = query.value(i).toString();

	QMessageBox::information(this, "data", str);

    new QListWidgetItem(str, m_list);    
  }

Code: Alles auswählen

bool Gui_Starter::OpenDB(int modus)
{   /* modus = 0=:memory:  1=STATIC_DB_FILE (copy to this file , empity befor)  404=kill_all */
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    
     switch(modus)
      {
         /* #################open ram db##################  */
         case 0:
              if (db.open()) {
              db.close();
              }
              db.setDatabaseName(":memory:");
              if (!db.open()) {
              is_DB_open = false;
              return false;
              }
              is_DB_open = true;
              return true;
         break;
         /* ###############open file db###################  */
         case 1:
              if (db.open()) {
              db.close();
              }
              db.setDatabaseName( STATIC_DB_FILE );
              if (!db.open()) {
              is_DB_open = false;
              return false;
              }
              is_DB_open = true;
              return true;
         break;
         /* ################close all#####################  */
         default: 
              if (db.open()) {
              db.close();
              }
              if (!db.open()) {
              is_DB_open = false;
              return false;
              } else {
              is_DB_open = true;
              return true;
              }            
      }
}

Code: Alles auswählen

#ifndef CONNECTION_H
#define CONNECTION_H

#include <QSqlDatabase>
#include <QMessageBox>
#include <QFile>
#include <QString>

// Database connection to SQLite
static bool createConnection() {
// Filename of the database
QString dbname = "test.db";
// Connection to SQLite
QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
// Check wether the database exists to avoid that it
// will be created if it doesn't exist
if (!QFile::exists(dbname)) {
QMessageBox::critical(0, (("Tipp10")),
			("Die SQLite Datenbank konnte leider nicht gefunden werden.\n\nDie Anwendung wird nun beendet."));
return false;
}
// Set database
db.setDatabaseName(dbname);
// Open the database
if (!db.open()) {
QMessageBox::critical(0, ("Tipp10"), ("Die Verbindung zur Datenbank SQLite ist leider fehlgeschlagen.\n"Die Anwendung wird nun beendet."));
        return false;
}
QSqlQuery query;
    query.exec("create table lect (id int primary key, "
               "lect_text varchar(80))");
    query.exec("insert into lect values(101, 'Funktioniert')");
    query.exec("insert into lect values(102, Juhuu)");
    query.exec("insert into lect values(103, 'Test')");
return true;

#endif // CONNECTION_H

Code: Alles auswählen

/* check the file db if is sqlite3 format....  */
bool Sqlitedb::check_file_db()
{
   bool ok=false;
   QString first_line = file_get_line(curDBFilename,1);  /* return QString from first line or "" */
   
     QFile file(curDBFilename);
         /*  check befor sqlite3 write a new file! */
         if (!file.exists()) {
         lastErrorMessage = QString( "File \"%1\" could not be read" ).arg( file.fileName() );
         return ok;   
         }
         if (first_line.size() < 1) {
         lastErrorMessage = QString("File could not be read");
         return ok;  
         }      
         if (!first_line.startsWith("SQLite format 3")) {
         lastErrorMessage = QString("File is not a SQLite 3 database");
         return ok;  
        } 
return true;
}

Code: Alles auswählen

bool Database::correctDatabaseFileVersion(const QString &filename)
{
  QFile dbfile(filename);

  if (! dbfile.open(QIODevice::ReadOnly)) {
    QMessageBox::critical(0, qApp->tr("Can't open database"),
        qApp->tr("Unable to open the database file for reading.") + "\n\n" +
                 m_msg_app_exit, QMessageBox::Cancel, QMessageBox::NoButton);
    return false;
  }

  QTextStream in(&dbfile);
  QString contents = QString("");

  if (! in.atEnd())
    contents = in.readLine();  // Unlimited, although only 16 chars needed.

  //QMessageBox::information(0, "db", QString::number(contents.length()) + "\n" + contents);

  dbfile.close();

  if (! contents.startsWith("SQLite format 3")) {
    QMessageBox::critical(0, qApp->tr("Can't open database"),
      qApp->tr("File is not a SQLite 3 database.") + "\n\n" +
               m_msg_app_exit, QMessageBox::Cancel, QMessageBox::NoButton);
    return false;
  }

  return true;
}

Code: Alles auswählen

QString file_get_line(QString fullFileName,int linenr)
{
    QString result;  
    QFile file( fullFileName );
    if( file.open( QIODevice::ReadOnly | QIODevice::Text ) ) {
       QTextStream in( &file );
       int currentLineNr = 0; // or 1
       while( ! in.atEnd() ) {
          QString line( in.readLine() );
          if( currentLineNr == linenr ) {   /* only rewrite here .. lineNr */
             result = line;
             break;
          }
          currentLineNr += 1;
          /*qDebug() << "### linerr  " << currentLineNr; */
       }
    }
    return result;
}