QT to realize the simple use of SQLite database

qt Realization sql operation , First add in the project file

QT+=sql

The required header file

#include<QDebug>
#include<QDir>
#include<QtSql/QSqlDatabase>
#include<QtSql/QSqlError>
#include<QtSql/QSqlTableModel>
#include<QtSql/QSqlQuery>

stay mainwindow.h Define variables in , For database operations

    QSqlDatabase db;
    QSqlTableModel *model;
    int currentSelectRow;

Define the database initialization function

bool MainWindow::initDB(){
    // load sqlite drive 
    if(QSqlDatabase::contains("qt_sql_default_connection")){
        db=QSqlDatabase::database("qt_sql_default_connection");
    }else{
        db=QSqlDatabase::addDatabase("QSQLITE");
    }
    // Determine whether the database file exists 
    bool dbFile = QFile::exists(QDir::currentPath()+"/mydb.db");
    // Open database , If the database file does not exist, it will be created automatically 
    db.setDatabaseName(QDir::currentPath()+"/mydb.db");
    if(!db.open()){
        qDebug()<<"database open error!"<<db.lastError();
        return false;
    }
    QSqlQuery query(db);
    // If you have not created a database file , Create a new table 
    if(!dbFile){
        query.exec("CREATE TABLE table_1 ("
                   "id INTEGER PRIMARY KEY AUTOINCREMENT, "
                   "name text, "
                   "age integer)"
                   );
    }

    model=new QSqlTableModel();
    model->setTable("table_1");
    model->select();
    ui->tableView->setModel(model);
    // Settings table is not editable 
    ui->tableView->setEditTriggers(QAbstractItemView::NoEditTriggers);
}

stay main Reference... In function

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    w.initDB();
    return a.exec();
}

stay ui Design graphical interface in editor

Select the row where the current cell is located , And display the selected data

void MainWindow::on_tableView_clicked(const QModelIndex &index)
{
    currentSelectRow=ui->tableView->currentIndex().row();
    ui->tableView->selectRow(currentSelectRow);
    // Display the selected data 
    ui->lineEdit->setText(model->data(model->index(currentSelectRow,0)).toString());
    ui->lineEdit_2->setText(model->data(model->index(currentSelectRow,1)).toString());
    ui->lineEdit_3->setText(model->data(model->index(currentSelectRow,2)).toString());

}

Define the callback function for adding buttons , Implement data addition

void MainWindow::on_pushButton_2_clicked()
{
    int rowNum=model->rowCount();
    model->insertRow(rowNum);
    model->setData(model->index(rowNum,1),ui->lineEdit_2->text());
    model->setData(model->index(rowNum,2),ui->lineEdit_3->text());

    model->submitAll();
    model->select();
}

Define the callback function for the delete button , Realize data deletion

void MainWindow::on_pushButton_3_clicked()
{
    model->removeRow(currentSelectRow);
    model->submitAll();
    model->select();
}

Define the callback function of the Modify button , Realize data modification

void MainWindow::on_pushButton_4_clicked()
{
    model->setData(model->index(currentSelectRow,1),ui->lineEdit_2->text());
    model->setData(model->index(currentSelectRow,2),ui->lineEdit_3->text());
    model->submitAll();
    model->select();
}

Define the callback function of the query button , Realize to name Fuzzy query of

void MainWindow::on_pushButton_clicked()
{
    if(ui->lineEdit_4->text().isEmpty())
    {
        model->setFilter("");
    }else{
        QString str(ui->lineEdit_4->text());
        model->setFilter("name like '%"+str+"%'");
    }
    model->select();
}

effect ：