$ cat main.c 
#include <mpi.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[]){

    MPI_Init(&argc,&argv);

    MPI_Finalize();

    return 0;
}

$ mpicc main.c -lm -std=c99 -g -O0 -o main && valgrind --tool=memcheck  mpirun -np 4 ./main
==409== Memcheck, a memory error detector
==409== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==409== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==409== Command: mpirun -np 4 ./main
==409== 
==409== Invalid read of size 8
...
==409== ERROR SUMMARY: 507 errors from 2 contexts (suppressed: 4 from 4)

ssh 192.168.0.*

export PATH=$PATH:/usr/lib64/openmpi/bin
export LD_LIBRARY_PATH=/usr/lib64/openmpi/lib

$ mpirun -np 2 hostname

$ mpirun -hostname /var/cluster/hosts.txt  -np 2 hostname

CREATE TABLE TestDict (    
    "id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
    "name" varchar(20) NOT NULL
);
CREATE TABLE TestTable (
    "id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
    "dict_id" integer NOT NULL,
    "value" real NOT NULL,
    FOREIGN KEY("dict_id") REFERENCES TestDict
);

INSERT INTO TestDict ("name") VALUES ("first element");
INSERT INTO TestDict ("name") VALUES ("second element");

INSERT INTO TestTable ("dict_id","value") VALUES ("1","22");
INSERT INTO TestTable ("dict_id","value") VALUES ("2","32");

#include <QtGui>
#include <QtSql>

int main(int argc, char *argv[]){
	QApplication app(argc,argv);
	QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
	db.setDatabaseName("test.db");
	if(!db.open()) {
            qDebug() << "open error";
	    return 1;
	}
	QSqlRelationalTableModel model;
	model.setTable("TestTable");
	model.setRelation(model.fieldIndex("dict_id"), QSqlRelation("TestDict", "id", "name"));
	//model.setFilter(tr("TestTable.dict_id=TestDict.id AND TestDict.name='first element'"));
	model.setFilter("dict_id=1");
	QTableView view;
	view.setModel(&model);
        view.setItemDelegate(new QSqlRelationalDelegate(&view)); 
	view.show();
	model.select();
	return app.exec();
}

sqlite>  select TestTable.id, TestTable.dict_id, TestTable.value from TestTable,TestDict WHERE TestTable.dict_id=TestDict.id AND TestDict.name='first element';
1|1|22.0

sqlite> select TestTable.id, TestDict.name, TestTable.value from TestTable,TestDict WHERE TestTable.dict_id=TestDict.id AND TestDict.name='first element';
1|first element|22.0

// при открытии документа делаю
model = new QSqlRelationalTableModel(this);
proxy = new QSortFilterProxyModel(this);
proxy->setSourceModel(model);

// при работе с таблицей
model->setTable("TestTable");
model->setRelation(1, QSqlRelation("Dict1", "id", "name"));
view->setModel(proxy);

view->setModel(model);

view->setModel(proxy);

QSortFilterProxyModel *proxy;
QSqlRelationalTableModel *model;
MyView *view; // наследник QTableView

QSortFilterProxyModel *proxy;
QSqlRelationalTableModel *model;
MyView *view;

// в конструкторе
view = new MyView

// в методе открытии документа
model = new QSqlRelationalTableModel(this);
model->setEditStrategy(QSqlTableModel::OnManualSubmit);
proxy = new QSortFilterProxyModel(this);
proxy->setSourceModel(model);

// при выборе таблицы для работы (редактирования)
    // для всех таблиц (кроме одной)
    view->setModel(model);
    // для одной
    view->setModel(proxy);

// в методе сохранения действую так:
QSqlTableModel *md = qobject_cast<QSqlTableModel*>(model()); // вот здесь то и проблема
md->database().transaction();
// ...

QWidgetAction *filter1 = new QWidgetAction(this);
filter1->setDefaultWidget(new QLineEdit(this));
toolForFilters->addAction(filter1);
addToolBar(Qt::TopToolBarArea,toolForFilters);

connect(что типа this->toolBar()-> ... filter1,SIGNAL(textChanged(const QString&)),document,SLOT(setFilter1(const QString&)))

qmake -project && qmake QT+=sql QMAKE_CXXFLAGS+=-fopenmp && make 

undefined reference to `GOMP_loop_static_start'
undefined reference to `GOMP_loop_static_next'
undefined reference to `GOMP_loop_end_nowait'
undefined reference to `GOMP_parallel_start'
undefined reference to `GOMP_parallel_end'

void MyWidget::openDatabase(){

    {
	    QString name;
	    {
                  QSqlDatabase db = QSqlDatabase::database();
                  if (db.isOpen()) 
		  { 
           	     db.close(); 
		     name = db.connectionNames()[0];
	             delete model;
                  }
	    }
       QSqlDatabase::removeDatabase(name);
    }

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

    db.setDatabaseName("test.sqlite");
    if(!db.open()) {
        QMessageBox::critical(0,QObject::tr("Ошибка"),db.lastError().text());
    }

    model = new QSqlTableModel(this);
    // ...
}

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

void MyView::openDatabase(){
   QSqlTableModel *m = qobject_cast<QSqlTableModel*>(model());
   m->database().setDatabaseName("test.sqlite3");
   if(!m->database().open()) {
       QMessageBox::critical(0,QObject::tr("Ошибка открытия"),m->database().lastError().text());
    }
}

QSqlDatabasePrivate::database: unable to open database: " " 

class MyView: public QTableView {
Q_OBJECT
public:
    MyView(QWidget * parent = 0);
public slots:
    void saveData();
};

class MyWidget: public QWidget { 
Q_OBJECT
    QSqlRelationalTableModel *model;
    MyView *view;
public:
    MyWidget(QWidget *parent = 0);
};

MyWidget::MyWidget(QWidget *parent): QWidget(parent){
    QVBoxLayout * layout = new QVBoxLayout;
    setLayout(layout);

    model = new QSqlRelationalTableModel(this);
    model->setTable("testtable");
    model->setRelation(0, QSqlRelation("dict", "dict_id", "name"));
    model->select(); 
    model->setEditStrategy(QSqlTableModel::OnManualSubmit);

    view = new MyView;
    view->setModel(model);
    view->setItemDelegate(new QSqlRelationalDelegate(view));
    layout->addWidget(view,5);

    QPushButton *bSave = new QPushButton(QObject::tr("&Сохранить"));
    QObject::connect(bSave,SIGNAL(clicked()),view,SLOT(saveData()));
    layout->addWidget(bSave,1);
}

MyView::MyView(QWidget *parent): QTableView(parent){}

void MyView::saveData(){
    if(((QSqlTableModel *) model())->submitAll()) qDebug() << "ok" ;
}

CREATE TABLE "dict" (    
    "dict_id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
    "name" varchar(20) NOT NULL
);
CREATE TABLE "testtable" (
    "dict_id" integer,
    "value" real NOT NULL,
    FOREIGN KEY(dict_id) REFERENCES dict
);

INSERT INTO dict ("name") VALUES ("A");
INSERT INTO dict ("name") VALUES ("B");

INSERT INTO testtable VALUES ("1",2.2);
INSERT INTO testtable VALUES ("2",6.6);

x_id   y_id     value
1      1        12
1      2        22
1      3        25
2      1        1.1
2      2        2.2
2      3        4.4
//...

x/y   1     2     3
1     12    22    25
2     1.1   2.2   4.4
3    .....

model = new MyTableModel;
// ...
view = new MyTableView;
layout->addWidget(view);
//...

void MyTableView::resizeEvent(QResizeEvent *event)
{
  resizeRowsToContents();
  resizeColumnsToContents();
}

model->setTable("TestTable");
view->setModel(model);
model->setHeaderData(1,Qt::Horizontal,tr("Имя")); 
// ...
model->select();
view->hideColumn(0); // idx
updateGeometry();

idx type   object
1    0     объект1
5    1     объект2
13   2     объект3

QRegExp rxe("^[a-z]+@[a-z]+$");
QValidator *validator = new QRegExpValidator(rxe,parent);
lineEditor->setValidator(validator);

SModel *m =qobject_cast<SModel*>(model());// main.cpp:61

g++ -c -m64 -pipe -O2 -Wall -W -D_REENTRANT -DQT_WEBKIT -DQT_NO_DEBUG -DQT_SQL_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++-64 -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtSql -I/usr/include/qt4 -I. -I. -o main.o main.cpp
In file included from /usr/include/qt4/QtSql/qsqlrelationaltablemodel.h:45:0,
                 from /usr/include/qt4/QtSql/qsqlrelationaldelegate.h:50,
                 from /usr/include/qt4/QtSql/QtSql:5,
                 from main.cpp:2:
/usr/include/qt4/QtSql/qsqltablemodel.h: In instantiation of ‘void QSqlTableModel::qt_check_for_QOBJECT_macro(const T&) const [with T = SModel]’:
/usr/include/qt4/QtCore/qobject.h:378:5:   required from ‘T qobject_cast(QObject*) [with T = SModel*]’
main.cpp:61:59:   required from here
/usr/include/qt4/QtSql/qsqltablemodel.h:61:5: error: void value not ignored as it ought to be
make: *** [main.o] Ошибка 1

if(условие1){
   sqlite3 *db;
   sqlite3_open(mysqlitefile, &db);
   zRequest = "SELECT ... ? ...";
   sqlite3_stmt *stmt; 
   sqlite3_prepare_v2(db, zRequest,-1,&stmt,0);
   sqlite3_bind_...;
   sqlite3_step(stmt);
   val1 = sqlite3_column_double(stmt,0);
   ...
   sqlite3_reset(stmt);
   sqlite3_finalize(stmt);
   sqlite3_close(db);
}

// ...

if(условие2){
   sqlite3 *db;
   sqlite3_open(mysqlitefile, &db);
   zRequest = "UPDATE ... ? ...";
   sqlite3_stmt *stmt; 
   sqlite3_prepare_v2(db, zRequest,-1,&stmt,0);
   sqlite3_bind_...;
   sqlite3_step(stmt); // вот тут ошибка database is locked
   ...
   sqlite3_finalize(stmt);
   sqlite3_close(db);
}

sqlite3_open_v2(mysqlitefile, &db, SQLITE_OPEN_READWRITE, NULL)

int main(int argc, char **argv){
  sqlite3 *db;
  sqlite3_open(argv[1], &db);
  sqlite3_stmt *stmt;
  char const * sqlRequest = "INSERT INTO MyTable (dict_id, value) VALUES (?,?);";
  for(int n=1; n<=2;++n){
              if(sqlite3_prepare(db, sqlRequest,-1,&stmt,0))
                       fprintf(stderr, "error1: %s\n", sqlite3_errmsg(db));
              sqlite3_bind_int(stmt,1,n); 
              sqlite3_bind_double(stmt,2,3.14*n); 
              if(sqlite3_step(stmt)  != SQLITE_OK) 
                       fprintf(stderr, "error2: %s\n", sqlite3_errmsg(db));
              sqlite3_reset(stmt);
  }
  sqlite3_finalize(stmt);
  sqlite3_close(db);
  return 0;
}

error2: unknown error
error2: unknown error

CREATE TABLE "Dict" (
    "id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
    "name" varchar(2) NOT NULL,
    "note" varchar(100) NOT NULL
)
;
CREATE TABLE "MyTable" (
    "dict_id" integer NOT NULL REFERENCES "Dict" ("id"),
    "value" real NOT NULL,
    PRIMARY KEY( "dict_id" )
)
;
CREATE INDEX "MyTable_0137dbe1" ON "MyTable" ("dict_id");

INSERT INTO Dict ("name", "note") VALUES ("Линукс","Ubuntu, Debian, ...");
INSERT INTO Dict ("name", "note") VALUES ("Виндовс","XP, 7, ...");