Database01.pro

SOURCES+=\

   main.cpp\

   Contact.cpp

QT+=gui widgets sql

CONFIG+=C++11

HEADERS+=\

   Contact.h

Contact.h

#ifndef CONTACT_H

#define CONTACT_H

#include <QWidget>

#include <QSqlTableModel>

#include <QTableView>

#include <QLineEdit>

#include <QPushButton>

class Contact : public QWidget

{

    Q_OBJECT

public:

    explicit Contact(QWidget *parent = 0);

    QSqlTableModel* _model;

    QTableView* _view;

    QLineEdit* _filter;

    QPushButton* _add;

    QPushButton* _del;

    QPushButton* _reset;

    QPushButton* _submit;

signals:

public slots:

    void slotModelDataChanged(QModelIndex,QModelIndex);

    void slotFilterChanged(QString filter);

};

#endif // CONTACT_H

Contact.cpp

#include "Contact.h"

#include <QVBoxLayout>

#include <QHBoxLayout>

#include <QSqlRecord>

#include <QCompleter>

#include <QDebug>

Contact::Contact(QWidget *parent) :

    QWidget(parent)

{

    //创建一个QSqlTableModel

    _model = new QSqlTableModel;

    //创建QTable

    _view = new QTableView;

    //view里面设置model

    _view->setModel(_model);

    _model->setTable("tcontact");

    //手动提交

    _model->setEditStrategy(QSqlTableModel::OnManualSubmit);

    connect(_model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),

            this, SLOT(slotModelDataChanged(QModelIndex,QModelIndex)));

    _model->select();

    // set Layout

    QVBoxLayout* vBox = new QVBoxLayout(this);

    vBox->addWidget(_view);

    QHBoxLayout* hBox = new QHBoxLayout;

    vBox->addLayout(hBox);

    //添加add

    hBox->addWidget(_filter = new QLineEdit, 1);

    hBox->addWidget(_add=new QPushButton("Add"));

    hBox->addWidget(_del=new QPushButton("Del"));

    hBox->addWidget(_reset=new QPushButton("Reset"));

    hBox->addWidget(_submit=new QPushButton("Submit"));

    connect(_add, &QPushButton::clicked, [&](){

        QSqlRecord record = _model->record();

        _model->insertRecord(-1, record);

    });

    connect(_del, &QPushButton::clicked, [&](){});

    connect(_reset, &QPushButton::clicked, [&](){});

    connect(_submit, &QPushButton::clicked, [&](){

        _model->submitAll();

    });

    //模糊查询

    connect(_filter, SIGNAL(textChanged(QString)),

            this, SLOT(slotFilterChanged(QString)));

    slotModelDataChanged(QModelIndex(), QModelIndex());

}

void Contact::slotFilterChanged(QString filter)

{

    if(filter.isEmpty())

    {

        _model->setFilter("");

        _model->select();

        return;

    }

    //  username like filter or password like  filter .......

    QSqlRecord record = _model->record();

    QString modelFilter;

    for(int i=0; i<record.count(); ++i)

    {

        if(i!=0)

        {

            modelFilter += " or ";

        }

        QString field = record.fieldName(i);

        QString subFilter = QString().sprintf("%s like ‘%%%s%%‘", field.toUtf8().data(), filter.toUtf8().data());

        //  qDebug() << subFilter;

        modelFilter += subFilter;

    }

    qDebug() << modelFilter;

    _model->setFilter(modelFilter);

    _model->select();

}

void Contact::slotModelDataChanged(QModelIndex,QModelIndex)

{

    QStringList strList;

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

    {

        QSqlRecord record = _model->record(i);

        for(int j=0; j<record.count(); ++j)

        {

            QVariant var = record.value(j);

            if(var.isNull()) continue;

            strList << var.toString();

        }

    }

    qDebug() << strList;

    QCompleter* completer=new QCompleter(strList);

    _filter->setCompleter(completer);

}

main.cpp

#include <QApplication>

#include "Widget05.h"

#include <QSqlDatabase>

#include <QSqlError>

#include <QDebug>

#include "Contact.h"

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

{

    QApplication app(argc,argv);

    /*QT可以操作 QSLITE QODBC,QPLSQL 这些数据库*/

    //下面表示使用mysql数据库，因为这里的db没有用到db，所以可以把它放在main中

    //本质：在QT里面打开一个数据库之后，就会保存一个数据库连接，

    //其它的位置就可以任意使用这个全局的变量了

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

    db.setHostName("127.0.0.1");  //设置数据库所在位置

    db.setUserName("root");       //设置数据库的用户名

    db.setPassword("123456");     //设置数据库的密码

    db.setDatabaseName("d0718");  //设置数据库名称

    bool bRet = db.open();        //打开数据库连接

    if(bRet == false)

    {

        //说明可以通过db.lastError()的方式得到错误信息

        qDebug() << "error open database" << db.lastError().text();

        exit(0);

    }

    qDebug() << "open database success";

    //注意Widget02要写在上面代码的下面

    Contact c;

    c.show();

    return app.exec();

}

运行结果：