我正在创建一个用于修改SQLite数据库的简单应用程序。
我尝试在MainWindow::on_AddButton_clicked()
方法中添加新行,但是当我使用MainWindow::on_reselectTable_clicked()
方法重新选择SqlTableView
时,所有新行都被删除了。
MainWindow.h:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QtSql/QSqlDatabase>
#include <QtSql/QSqlError>
#include <QtSql/QSqlTableModel>
#include <QDebug>
#include <QtSql>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
private slots:
void on_AddButton_clicked();
void on_tableView_clicked(const QModelIndex &index);
void on_DeleteButton_clicked();
void on_comboBox_currentIndexChanged(int index);
void on_submitButton_clicked();
void on_revertButton_clicked();
void on_reselectTable_clicked();
private:
Ui::MainWindow *ui;
QSqlDatabase db;
QSqlTableModel* model;
int currentRow;
};
#endif // MAINWINDOW_H
MainWindow.cpp:
#include "mainwindow.h"
#include "./ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
db = QSqlDatabase::addDatabase("QSQLITE");
db.setHostName("127.0.0.1");
//db = QSqlDatabase::addDatabase("QMYSQL");
db.setDatabaseName("../db/cities.db3");
if (db.open())
{
ui->statusbar->showMessage("Successful database connection: " + db.databaseName());
model = new QSqlTableModel(this, db);
model->setTable("cities");
model->setEditStrategy(QSqlTableModel::OnManualSubmit);
model->select();
ui->tableView->setModel(model);
//rui->tableView->setColumnHidden(0, true);
ui->tableView->setColumnHidden(1, true);
ui->tableView->setColumnHidden(2, true);
ui->tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
ui->tableView->setSortingEnabled(true);
}
else
{
ui->statusbar->showMessage("Connection error: " + db.lastError().databaseText());
}
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_tableView_clicked(const QModelIndex &index)
{
currentRow = index.row();
}
void MainWindow::on_comboBox_currentIndexChanged(int index)
{
qDebug() << index;
switch (index)
{
case 0:
model->setFilter("population > 0");
break;
case 1:
model->setFilter("population > 1000");
break;
case 2:
model->setFilter("population > 10000");
break;
case 3:
model->setFilter("population > 25000");
break;
case 4:
model->setFilter("population > 50000");
break;
case 5:
model->setFilter("population > 100000");
break;
case 6:
model->setFilter("population > 250000");
break;
case 7:
model->setFilter("population > 500000");
break;
case 8:
model->setFilter("population > 1000000");
break;
case 9:
model->setFilter("population > 2000000");
break;
case 10:
model->setFilter("population > 20000000");
default: // nop
break;
}
model->select();
}
void MainWindow::on_AddButton_clicked()
{
qDebug() << "inserting row:" << model->insertRow(model->rowCount());
}
void MainWindow::on_DeleteButton_clicked()
{
qDebug() << "deleting row:" << model->removeRow(currentRow);
model->select();
}
void MainWindow::on_submitButton_clicked()
{
model->submitAll();
}
void MainWindow::on_revertButton_clicked()
{
model->revertAll();
}
void MainWindow::on_reselectTable_clicked()
{
model->select();
}
CMakeList.txt
cmake_minimum_required(VERSION 3.5)
project(cities VERSION 0.1 LANGUAGES CXX)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
find_package(QT NAMES Qt5 COMPONENTS Widgets Sql REQUIRED)
find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Widgets Sql REQUIRED)
set(PROJECT_SOURCES
main.cpp
mainwindow.cpp
mainwindow.h
mainwindow.ui
)
add_executable(cities ${PROJECT_SOURCES})
if(SQLite3_FOUND)
include_directories(${SQLITE_INCLUDE_DIRS})
target_link_libraries(cities, ${SQLITE_LIBRARIES})
endif(SQLite3_FOUND)
target_link_libraries(cities PRIVATE Qt${QT_VERSION_MAJOR}::Widgets Qt${QT_VERSION_MAJOR}::Sql)
1条答案
按热度按时间368yc8dk1#
从QSqlTableModel::选择:
**注意:**调用select()将恢复所有未提交的更改并删除所有插入的列。
因此,在尝试调用
select()
之前,您需要提交更改,但是如果您这样做而没有填充新添加的行,它仍然无法工作。要检查原因,您可以使用:用途:
这将输出:
范例: