База данных

     ui->prep_viev->setColumnHidden(0,true);

     //Вывод таблицы Student

     Student=new QSqlTableModel(0,db);

     Student->setTable("Student");

     Student->select();

     Student->setEditStrategy(QSqlTableModel::OnManualSubmit);

     ui->stud_viev->setModel(Student);

     ui->stud_viev->setColumnHidden(0,true);

     //Вывод таблицы Plan

     Plan=new QSqlTableModel(0,db);

     Plan->setTable("Plan");

     Plan->select();

     Plan->setEditStrategy(QSqlTableModel::OnManualSubmit);

     ui->plan_viev->setModel(Plan);

     ui->plan_viev->setColumnHidden(0,true);

     //Вывод таблицы Prep_Plan

     Prep_Plan=new QSqlTableModel(0,db);

     Prep_Plan->setTable("Prep_Plan");

     Prep_Plan->select();

     Prep_Plan->setEditStrategy(QSqlTableModel::OnManualSubmit);

     //Вывод таблицы Inf_Stud

     Inf_Stud=new QSqlTableModel(0,db);

     Inf_Stud->setTable("Inf_Stud");

     Inf_Stud->select();

     Inf_Stud->setEditStrategy(QSqlTableModel::OnManualSubmit);

     //Вывод таблицы Inf_Disc

     Inf_Disc=new QSqlTableModel(0,db);

     Inf_Disc->setTable("Inf_Disc");

     Inf_Disc->select();

     Inf_Disc->setEditStrategy(QSqlTableModel::OnManualSubmit);

model44.setQuery("SELECT b_disc,b_prep FROM Prepodavatel, Disciplina, Inf_Disc WHERE Prepodavatel.ID_prep=Inf_Disc.ID_prep AND Inf_Disc.ID_disc=Disciplina.ID_disc");

     ui->tableView_2->setModel(&model44);

     //Вывод таблицы отчёт

     QSqlQueryModel *model = new QSqlQueryModel;

model->setQuery("SELECT b_disc,b_stud,c_stud,b_prep,b_plan,year_plan,year_prod,kurs,lec, labs, prakt, zach, exam FROM Disciplina,Student,Prepodavatel,Plan,Prep_Plan,Inf_Stud,Inf_Disc WHERE (Disciplina.ID_disc=Inf_Disc.ID_disc) AND (Prepodavatel.ID_prep=Inf_Disc.ID_prep) AND (Inf_Stud.ID_stud=Student.ID_stud) AND (Plan.ID_plan=Inf_Stud.ID_plan) AND (Prep_Plan.ID_disc=Disciplina.ID_disc) AND (Prep_Plan.ID_plan=Plan.ID_plan)");

    ui->tableView->setModel(model); 

Отображение кнопок:

ui->add_new_stud->setEnabled(false);

ui->del_new_stud->setEnabled(false);

ui->add_nagr->setEnabled(false);

ui->ok_nagruz->setEnabled(false);

ui->del_nagruz->setEnabled(false);

ui->ok_nagruz->setEnabled(false); 

Сигналы:

     //Сигналы  для вкладки "Дисциплины  и Преподаватели"

     QObject::connect(ui->add_disc,SIGNAL(clicked()),this,SLOT(add_dis()));

     QObject::connect(ui->del_disc,SIGNAL(clicked()),this,SLOT(del_dis()));

     QObject::connect(ui->ok_disc,SIGNAL(clicked()),this,SLOT(ok_disc()));

     QObject::connect(ui->disc_prep,SIGNAL(clicked()),this,SLOT(disc_prep()));

     QObject::connect(ui->add_prep,SIGNAL(clicked()),this,SLOT(add_prep()));

     QObject::connect(ui->del_prep,SIGNAL(clicked()),this,SLOT(del_prep()));

     QObject::connect(ui->ok_prep,SIGNAL(clicked()),this,SLOT(ok_prep()));

     //Сигналы  для вкладки "Студенты  и Учебные планы"

     QObject::connect(ui->add_plan,SIGNAL(clicked()),this,SLOT(add_plan()));

QObject::connect(ui->del_plan,SIGNAL(clicked()),this,SLOT(del_plan()));

QObject::connect(ui->ok_plan,SIGNAL(clicked()),this,SLOT(ok_plan()));

QObject::connect(ui->can_plan,SIGNAL(clicked()),this,SLOT(can_plan()));

QObject::connect(ui->add_stud,SIGNAL(clicked()),this,SLOT(add_stud()));

QObject::connect(ui->del_stud,SIGNAL(clicked()),this,SLOT(del_stud()));

QObject::connect(ui->ok_stud,SIGNAL(clicked()),this,SLOT(ok_stud()));

QObject::connect(ui->can_stud,SIGNAL(clicked()),this,SLOT(can_stud()));

QObject::connect(ui->add_new_stud,SIGNAL(clicked()),this,SLOT(add_new_stud()));

QObject::connect(ui->del_new_stud,SIGNAL(clicked()),this,SLOT(del_new_stud()));

QObject::connect(ui->plan_viev,SIGNAL(clicked(QModelIndex)), this,

this,SLOT(plan_and_students()));

QObject::connect(ui->add_nagr,SIGNAL(clicked()),this,SLOT(add_nagr()));

QObject::connect(ui->del_nagruz,SIGNAL(clicked()),this,SLOT(del_nagruz()));

QObject::connect(ui->ok_nagruz,SIGNAL(clicked()),this,SLOT(ok_nagruz()));

QObject::connect(ui->stud_viev,SIGNAL(clicked(QModelIndex)),this,SLOT(st_viev()));

QObject::connect(ui->listView,SIGNAL(clicked(QModelIndex)),this,SLOT(st()));

QObject::connect(ui->nagruz_viev_2,SIGNAL(clicked(QModelIndex)),this,SLOT(izm_nag()));

ui->add_new_stud->setEnabled(false);

ui->del_new_stud->setEnabled(false);

ui->add_nagr->setEnabled(false);

ui->ok_nagruz->setEnabled(false);

ui->del_nagruz->setEnabled(false);

ui->ok_nagruz->setEnabled(false);

     //Сигналы для вкладки "Отчёт"

     QObject::connect(ui->Refresh,SIGNAL(clicked()),this,SLOT(Refresh()));

     QObject::connect(ui->Report,SIGNAL(clicked()),this,SLOT(Report())); 

  ComboBox для вкладки "Отчёт":

QSqlQuery q("select distinct b_stud from Student");

int i=0;

QString str;

while(q.next())

{

str=q.value(0).toString();

ui->comboBox_2->addItem(str,i);

i++;

} 

Добавить  запись:

     //Описание  функции кнопки  Добавить

void MainWindow::add_dis()

{

add_disc form;

form.exec();

Disciplina->select();

}

void MainWindow::add_prep()

{

add_prepod form;

form.exec();

Prepodavatel->select();

}

void MainWindow::add_plan()

{

Plan->insertRecord(-1,QSqlRecord::QSqlRecord());

}

void MainWindow::add_stud()

{

Student->insertRecord(-1,QSqlRecord::QSqlRecord());

}

void MainWindow::add_nagr()

{

Prep_Plan->insertRecord(-1,QSqlRecord::QSqlRecord());

add_nagruz form;

form.exec();

Prep_Plan->select();

int a=ui->plan_viev->currentIndex().row();

QSqlRecord record1=Plan->record(a);

model1.setQuery(tr("SELECT b_disc,kurs,lec,labs,prakt,zach,exam FROM Disciplina, Plan, Prep_Plan WHERE Disciplina.ID_disc=Prep_Plan.ID_disc AND Prep_Plan.ID_plan=Plan.ID_plan AND (b_plan=\"%1\") AND (year_plan=\"%2\") AND (year_prod=\"%3\")").arg(record1.value("b_plan").toString()).arg(record1.value("year_plan").toInt()).arg(record1.value("year_prod").toInt()));

ui->nagruz_viev_2->setModel(&model1);

}

void MainWindow::add_new_stud()

{

int a=ui->plan_viev->currentIndex().row();

QSqlRecord record1=Plan->record(a);

int n=ui->stud_viev->currentIndex().row();

QSqlRecord record2=Student->record(n);

int str=record1.value("ID_plan").toInt();

int str1=record2.value("ID_stud").toInt();

QSqlQuery query;

query.prepare("INSERT INTO Inf_Stud (ID_stud, ID_plan)"

"VALUES (:id1, :id2)");

query.bindValue(":id1",str1);

query.bindValue(":id2",str);

query.exec();

model11.setQuery(tr("SELECT b_stud FROM Student, Inf_Stud, Plan WHERE (Student.ID_stud=Inf_Stud.ID_stud) AND (Inf_Stud.ID_plan=Plan.ID_plan) AND (b_plan=\"%1\") AND (year_plan=\"%2\") AND (year_prod=\"%3\")").arg(record1.value("b_plan").toString()).arg(record1.value("year_plan").toInt()).arg(record1.value("year_prod").toInt()));

ui->listView->setModel(&model11);

Inf_Stud->submitAll();

ui->add_new_stud->setEnabled(false);

} 

Удалить запись:

void MainWindow::del_dis()

{

int a=ui->disc_viev->currentIndex().row();

QSqlRecord record1=Disciplina->record(a);

bool k=false,l=false;

for(int i=0;i<Prep_Plan->rowCount();i++)

{

QSqlRecord record2=Prep_Plan->record(i);

if(record1.value("ID_disc").toInt()==record2.value("ID_disc").toInt())

k=true;

}

for(int i=0;i<Inf_Disc->rowCount();i++)

{

QSqlRecord record2=Inf_Disc->record(i);

if(record1.value("ID_disc").toInt()==record2.value("ID_disc").toInt())

l=true;

}

if (k==false&&l==false)

{

Disciplina->removeRow(a);

Disciplina->submitAll();

}

else

{

int r = QMessageBox::question(this, tr("DELETE DISCIPLINE"),

tr("Delete \"%1\" and its links?")

.arg(record1.value("b_disc").toString()),

QMessageBox::Yes | QMessageBox::Default,

QMessageBox::No | QMessageBox::Escape);

if (r == QMessageBox::No)

return;

else

{

for(int i=0;i<Prep_Plan->rowCount();i++)

{

QSqlRecord record2=Prep_Plan->record(i);

if(record1.value("ID_disc").toInt()==record2.value("ID_disc").toInt())

{

Prep_Plan->removeRow(i);

Prep_Plan->submitAll();

}

}

for(int i=0;i<Inf_Disc->rowCount();i++)

{

QSqlRecord record2=Inf_Disc->record(i);

if(record1.value("ID_disc").toInt()==record2.value("ID_disc").toInt())

{

Inf_Disc->removeRow(i);

Inf_Disc->submitAll();

}