QT項目--簡單的數據庫可視化系統

簡單的數據庫可視化系統

項目功能：用戶可以通過界面互動的方式對數據庫（mySql）進行查詢，更新，刪除，插入的操作。
項目簡介：利用qt框架庫+c++語言實現，用戶在使用前需要先登錄系統（用戶登錄後，信息會自動記錄在配置文件中，之後會自動填寫），然後選擇對應的操作，之後在彈出的對話框中輸入對應的信息即可。系統會根據用戶輸入的內容自動生成sql語言並自動去執行，最後將執行結果返回。
技術點：配置文件，qt數據操作，自定義對話框
項目難點：自動調節大小對話框，由於不同的表的屬性個數是不同的所以，對話需要根據對話框中的內容，自動調節大小。
*這裏展示的是項目主要代碼，全部項目請移步下載：
https://github.com/llpig/windowsCode/tree/dev1/qt_DataBases/DataBases

項目截圖

項目代碼

custommessagebox.h

#ifndef CUSTOMMESSAGEBOX_H
#define CUSTOMMESSAGEBOX_H

#include <QMessageBox>
#include <QResizeEvent>
#include <QLabel>
#include <QPushButton>
#include <algorithm>
#include <QVector>
#include <QLineEdit>

using namespace std;

class CustomMessageBox : public QMessageBox
{
    Q_OBJECT
public:
    explicit CustomMessageBox(QWidget *parent = 0,QString="MessageBox");
    ~CustomMessageBox();
    //對話框可以根據其內容自動計算大小
    void adjustWindowSize(QSize windowSize);
    QSize addWidgetToMessageBox(QStringList stringList);
    QSize addWidgetToMessageBoxUpdate(QStringList stringList);
    int addPushButtonToMessageBox();
    QPushButton *m_CommitPushButton;
    QPushButton *m_CancelPushButtom;
    static QVector<QLineEdit*> m_LineEditVector;//用於保存創建的條形框
protected:
    int m_MessageBoxWidth;
    int m_MessageBoxHeight;
    static int m_LeftInterval;//窗口左間隔
    static int m_RightInterval;//窗口右間隔
    static int m_IntervalLR;//組件左右間隔
    static int m_IntervalUL;//組件上下間隔
    static int m_LineEditWidth;//條形框的寬
    void resizeEvent(QResizeEvent* event);
};

#endif // CUSTOMMESSAGEBOX_H

custommessagebox.cpp

#include "custommessagebox.h"

int CustomMessageBox::m_LeftInterval=15;
int CustomMessageBox::m_RightInterval=15;
int CustomMessageBox::m_IntervalLR=10;
int CustomMessageBox::m_IntervalUL=5;
int CustomMessageBox::m_LineEditWidth=110;
QVector<QLineEdit*> CustomMessageBox::m_LineEditVector;

CustomMessageBox::CustomMessageBox(QWidget *parent, QString titleText) : QMessageBox(parent)
{
    setWindowTitle(titleText);
    m_CommitPushButton=NULL;
    m_CancelPushButtom=NULL;
}

CustomMessageBox::~CustomMessageBox()
{

}

void CustomMessageBox::adjustWindowSize(QSize windowSize)
{
    m_MessageBoxWidth=windowSize.width();
    m_MessageBoxHeight=windowSize.height();
}

QSize CustomMessageBox::addWidgetToMessageBox(QStringList stringList)
{
    m_LineEditVector.clear();
    if(stringList.isEmpty())
    {
    return QSize(0,0);
    }
    int maxLabelWidth=0,labelHeight=0;
    for(int i=0;i<stringList.size();++i)
    {
        QLabel *label=new QLabel(stringList[i],this);
        label->setGeometry(m_LeftInterval,i*(label->height()+m_IntervalUL),label->width(),label->height());
        QLineEdit *lineEdit=new QLineEdit(this);
        lineEdit->setObjectName(stringList[i]);
        m_LineEditVector.push_back(lineEdit);
        maxLabelWidth=max(maxLabelWidth,label->width());
        labelHeight=label->height();
    }
    for(int i=0;i<stringList.size();++i)
    {
        m_LineEditVector[i]->setGeometry(maxLabelWidth+m_IntervalLR,i*(labelHeight+m_IntervalUL),m_LineEditWidth,labelHeight);
    }
    int messageBoxWidth=m_LeftInterval+m_RightInterval+maxLabelWidth+m_IntervalLR+m_LineEditWidth;
    int messageBoxHeight=stringList.size()*(labelHeight+m_IntervalUL);
    return QSize(messageBoxWidth,messageBoxHeight);
}

QSize CustomMessageBox::addWidgetToMessageBoxUpdate(QStringList stringList)
{
    m_LineEditVector.clear();
    if(stringList.isEmpty())
    {
        return QSize(0,0);
    }
    int maxLabelWidth=0,labelHeight=0;
    for(int i=0;i<stringList.size();++i)
    {
        QLabel *label=new QLabel(stringList[i],this);
        label->setGeometry(m_LeftInterval,(i+1)*(label->height()+m_IntervalUL),label->width(),label->height());
        QLineEdit *oldLineEdit=new QLineEdit(this);
        oldLineEdit->setObjectName(stringList[i]);
        m_LineEditVector.push_back(oldLineEdit);
        QLineEdit *newLineEdit=new QLineEdit(this);
        m_LineEditVector.push_back(newLineEdit);
        maxLabelWidth=max(maxLabelWidth,label->width());
        labelHeight=label->height();
    }
    int k=1;
    for(int i=0;i<m_LineEditVector.size();i+=2)
    {
        m_LineEditVector[i]->setGeometry(maxLabelWidth+m_IntervalLR,k*(labelHeight+m_IntervalUL),m_LineEditWidth,labelHeight);
        m_LineEditVector[i+1]->setGeometry(maxLabelWidth+m_LineEditWidth+2*m_IntervalLR,k*(labelHeight+m_IntervalUL),m_LineEditWidth,labelHeight);
        ++k;
    }
    QLabel *newLabel=new QLabel("更新後數據",this);
    newLabel->setGeometry(maxLabelWidth+m_LineEditWidth+2*m_IntervalLR,0,newLabel->width(),newLabel->height());
    QLabel *oldLabel=new QLabel("更新前數據",this);
    oldLabel->setGeometry(maxLabelWidth+m_IntervalLR,0,oldLabel->width(),oldLabel->height());
    int messageBoxWidth=m_LeftInterval+m_RightInterval+maxLabelWidth+2*m_IntervalLR+2*m_LineEditWidth;
    int messageBoxHeight=(stringList.size()+1)*(labelHeight+m_IntervalUL);
    return QSize(messageBoxWidth,messageBoxHeight);
}

int CustomMessageBox::addPushButtonToMessageBox()
{
    m_CommitPushButton=this->addButton("commit",QMessageBox::ActionRole);
    m_CancelPushButtom=this->addButton(QMessageBox::Cancel);
    return m_CancelPushButtom->height();
}

void CustomMessageBox::resizeEvent(QResizeEvent *event)
{
    setFixedSize(m_MessageBoxWidth,m_MessageBoxHeight);
}

databases.h

#ifndef DATABASES_H
#define DATABASES_H

#include <QFile>
#include <QVector>
#include <QtDebug>
#include <QSqlQuery>
#include <QSqlError>
#include <QSettings>
#include <QMessageBox>
#include <QSqlDatabase>
#include <QMainWindow>
#include <QMap>
#include <QFont>
#include <algorithm>
#include <QGroupBox>
#include "dblogin.h"
#include "custommessagebox.h"
using namespace std;
namespace Ui {
class DataBases;
}
enum OpType{Select,Update,Add,Delete};
class DataBases : public QMainWindow
{
    Q_OBJECT

public:
    static QString DataBasesName;
    explicit DataBases(QWidget *parent = 0);
    ~DataBases();
    void initWindow();
    QSqlDatabase* getDataBasePointer();


private slots:
    void on_DB_select_clicked();

    void on_DB_update_clicked();

    void on_DB_add_clicked();

    void on_DB_detele_clicked();

private:
    Ui::DataBases *ui;
    QSqlDatabase *DB_Mysql;//數據庫指針
    QSqlQuery *query;//數據庫執行指針
    QStringList m_MessageBoxInfo;//用於保存的對話框信息
    static QString configFileName;//配置文件名稱
    //創建配置文件
    void createConfigFile();
    //查詢當前數據中的表，並將表名寫入下拉框
    void selectTable();
    //創建數據庫操作的對話框(查詢，刪除，插入)
    bool createDialogBox(QString opName, QString tableName, OpType opType);
    //獲取表的描述
    QStringList getTabelDescribe(QString tableName);
    //判斷是否點擊的爲"commit"按鈕
    bool isCommitClicked(CustomMessageBox* messageBox);
    bool isCommitClickedUpdate(CustomMessageBox* messageBox);
    //將text的內容寫入展示框（文本框）中
    void addTextToShowBox(QString text);
};

#endif // DATABASES_H

databases.cpp

#include "databases.h"
#include "ui_databases.h"

QString DataBases::configFileName="DataBases.ini";
QString DataBases::DataBasesName="";

DataBases::DataBases(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::DataBases)
{
    ui->setupUi(this);
    query=NULL;
    DB_Mysql=new QSqlDatabase(QSqlDatabase::addDatabase("QMYSQL"));
    createConfigFile();
}

DataBases::~DataBases()
{
    delete ui;
}

QSqlDatabase *DataBases::getDataBasePointer()
{
    return DB_Mysql;
}

void DataBases::initWindow()
{
    setWindowTitle("數據庫可視化管理工具");
    ui->DB_lineEdit_DBname->setText(DataBasesName+".db");
    query=new QSqlQuery(*DB_Mysql);
    selectTable();
}

//查詢按鈕
void DataBases::on_DB_select_clicked()
{
    QString tableName=ui->DB_comboBox_tableName->currentText();
    if(!createDialogBox("信息查詢",tableName,Select))
    {
        return;
    }
    QString queries="",queryCond="",queryStr="";
    for(int i=0;i<m_MessageBoxInfo.size();i+=2)
    {
        if(m_MessageBoxInfo[i+1].isEmpty())
        {
            queries=queries+m_MessageBoxInfo[i]+",";
        }
        else
        {
            queryCond=queryCond+m_MessageBoxInfo[i]+" like '%"+m_MessageBoxInfo[i+1]+"%' and ";
        }
    }
    if(queries.isEmpty())
    {
        qDebug()<<"未檢測到需要查詢的內容"<<endl;
        return;
    }
    else if(queryCond.isEmpty())
    {
        queries.remove(queries.length()-1,1);
        queryStr=QString("Select %1 from %2;").arg(queries).arg(tableName);
    }
    else
    {
        queries.remove(queries.length()-1,1);
        queryCond.remove(queryCond.length()-5,5);
        queryStr=QString("Select %1 from %2 where %3;").arg(queries).arg(tableName).arg(queryCond);
    }
    addTextToShowBox("查詢內容:("+queries+")\n查詢結果：");
    int nums=queries.split(',').length();
    if(!queryStr.isEmpty())
    {
        if(query->exec(queryStr))
        {
            while(query->next())
            {
                for(int i=0;i<nums;++i)
                {
                    addTextToShowBox(query->value(i).toString()+",");
                }
                addTextToShowBox("\n");
            }
        }
        else
        {
            addTextToShowBox(query->lastError().text()+"\n");
        }
    }
}

//更新按鈕
void DataBases::on_DB_update_clicked()
{
    //更新（更新存在舊值和新值的替換關係，所以需要一個新的自定義控件）
    QString tableName=ui->DB_comboBox_tableName->currentText();
    if(!createDialogBox("信息更新",tableName,Update))
    {
        return;
    }
    QString queries="",queryCond="",queryStr="";
    for(int i=0;i<m_MessageBoxInfo.size();i+=3)
    {
        //需要修改的內容
        if(!m_MessageBoxInfo[i+1].isEmpty())
        {
            queryCond=queryCond+m_MessageBoxInfo[i]+" like '%"+m_MessageBoxInfo[i+1]+"%' and ";
        }
        //條件
        if(!m_MessageBoxInfo[i+2].isEmpty())
        {
            queries=queries+m_MessageBoxInfo[i]+" = '"+m_MessageBoxInfo[i+2]+"',";
        }
    }
    if(queries.isEmpty()||queryCond.isEmpty())
    {
        qDebug()<<"請輸入修改後的內容和修改的條件！"<<endl;
    }
    queries.remove(queries.length()-1,1);
    queryCond.remove(queryCond .length()-5,5);
    queryStr=QString("UpDate %1 Set %2 Where %3;").arg(tableName).arg(queries).arg(queryCond);
    if(query->exec(queryStr))
    {
        addTextToShowBox("符合條件的記錄已更改完成！\n");
    }
    else
    {
        addTextToShowBox(query->lastError().text()+"\n");
    }
}

//添加按鈕
void DataBases::on_DB_add_clicked()
{

    QString tableName=ui->DB_comboBox_tableName->currentText();
    if(!createDialogBox("信息添加",tableName,Add))
    {
        return;
    }
    QString queries="",queryCond="",queryStr="";
    for(int i=0;i<m_MessageBoxInfo.size();i+=2)
    {
        if(!m_MessageBoxInfo[i+1].isEmpty())
        {
            queries=queries+m_MessageBoxInfo[i]+",";
            queryCond=queryCond+"'"+m_MessageBoxInfo[i+1]+"',";
        }
    }
    if(queries.isEmpty())
    {
        qDebug()<<"請輸入需要插入的內容"<<endl;
        return;
    }
    queries.remove(queries.length()-1,1);
    queryCond.remove(queryCond.length()-1,1);
    queryStr=QString("Insert into %1 (%2) values (%3);").arg(tableName).arg(queries).arg(queryCond);
    if(query->exec(queryStr))
    {
        addTextToShowBox("記錄已成功添加！");
    }
    else
    {
        addTextToShowBox(query->lastError().text()+"\n");
    }
}

//刪除按鈕
void DataBases::on_DB_detele_clicked()
{
    QString tableName=ui->DB_comboBox_tableName->currentText();
    if(!createDialogBox("信息刪除",tableName,Delete))
    {
        return;
    }
    QString queryCond="",queryStr="";
    for(int i=0;i<m_MessageBoxInfo.size();i+=2)
    {
        if(!m_MessageBoxInfo[i+1].isEmpty())
        {
            queryCond=queryCond+m_MessageBoxInfo[i]+" like '%"+m_MessageBoxInfo[i+1]+"%' and ";
        }
    }
    if(queryCond.isEmpty())
    {
        qDebug()<<"請填寫需要刪除內容的條件"<<endl;
        return;
    }
    queryCond.remove(queryCond.length()-5,5);
    queryStr=QString("Delete from %1 where %2;").arg(tableName).arg(queryCond);
    qDebug()<<queryStr<<endl;
    if(query->exec(queryStr))
    {
        addTextToShowBox("符合條件的內容已經被刪除！\n");
    }
    else
    {
        addTextToShowBox(query->lastError().text());
    }
}


void DataBases::createConfigFile()
{
    //創建配置文件
    QFile *filePointer=new QFile();
    //如果配置文件不存在
    if(!filePointer->exists(configFileName))
    {
        filePointer->setFileName(configFileName);
        if(filePointer->open(QFile::WriteOnly))
        {
            filePointer->write("[USERNAME]\nusername=\n");
            filePointer->write("[PASSWORD]\npassword=\n");
            filePointer->write("[HOSTNAME]\nhostname=\n");
            filePointer->write("[PORT]\nport=\n");
            filePointer->write("[DATABASESNAME]\ndatabasesname=\n");
        }
        QSettings *iniPointer=new QSettings(configFileName,QSettings::IniFormat);
        iniPointer->setValue("USERNAME/username","root");
        iniPointer->setValue("HOSTNAME/hostname","localhost");
        iniPointer->setValue("PORT/port","3306");
        filePointer->close();
        delete iniPointer;
        delete filePointer;
    }
}


void DataBases::selectTable()
{
    QString sqlStr="show tables";
    query->exec(sqlStr);
    //遍歷語句的執行結果將結果依此加入下拉框中
    while(query->next())
    {
        ui->DB_comboBox_tableName->addItem(query->value(0).toString());
    }
}


bool DataBases::createDialogBox(QString opName, QString tableName, OpType opType)
{
    CustomMessageBox *dialogBox=new CustomMessageBox(this,opName);
    QSize boxSize;
    if(opType==Update)
    {
        boxSize=dialogBox->addWidgetToMessageBoxUpdate(getTabelDescribe(tableName));
    }
    else
    {
        boxSize=dialogBox->addWidgetToMessageBox(getTabelDescribe(tableName));
    }
    int boxHeight=dialogBox->addPushButtonToMessageBox();
    boxSize.setHeight(boxSize.height()+1.5*boxHeight);
    dialogBox->adjustWindowSize(boxSize);
    dialogBox->exec();
    if(opType==Update)
    {
        return isCommitClickedUpdate(dialogBox);
    }
    else
    {
        return isCommitClicked(dialogBox);
    }
}


QStringList DataBases::getTabelDescribe(QString tableName)
{
    QString sqlStr="Describe "+tableName;
    QStringList sqlResult;
    bool res=query->exec(sqlStr);
    while(res&&query->next())
    {
        sqlResult.push_back(query->value(0).toString());
    }
    return sqlResult;
}

bool DataBases::isCommitClicked(CustomMessageBox *messageBox)
{
    bool bRet=false;
    m_MessageBoxInfo.clear();
    if(messageBox->clickedButton()==messageBox->m_CommitPushButton)
    {
        bRet=true;
        for(int i=0;i<messageBox->m_LineEditVector.size();++i)
        {
            m_MessageBoxInfo.push_back(messageBox->m_LineEditVector[i]->objectName());
            m_MessageBoxInfo.push_back(messageBox->m_LineEditVector[i]->text());
        }
    }
    return bRet;
}

bool DataBases::isCommitClickedUpdate(CustomMessageBox *messageBox)
{
    bool bRet=false;
    m_MessageBoxInfo.clear();
    if(messageBox->clickedButton()==messageBox->m_CommitPushButton)
    {
        bRet=true;
        for(int i=0;i<messageBox->m_LineEditVector.size();i+=2)
        {
            m_MessageBoxInfo.push_back(messageBox->m_LineEditVector[i]->objectName());
            m_MessageBoxInfo.push_back(messageBox->m_LineEditVector[i]->text());
            m_MessageBoxInfo.push_back(messageBox->m_LineEditVector[i+1]->text());
        }
    }
    return bRet;
}


void DataBases::addTextToShowBox(QString text)
{
    //將文本框中的內容清空
    ui->DB_show->clear();
    ui->DB_show->textCursor().insertText(text);
}

dblogin.h

#ifndef DBLOGIN_H
#define DBLOGIN_H

#include <QDialog>
#include <QString>
#include <QSettings>
#include <QFile>
#include "databases.h"

#define  LOGINSUCCESS 0
#define  LOGINFAILURE 1

namespace Ui {
class DBLogin;
}

class DBLogin : public QDialog
{
    Q_OBJECT

public:
    explicit DBLogin(QWidget *parent = 0);
    ~DBLogin();
    QString getUserName();
    QString getPassWord();
    QString getHostName();
    QString getPort();
    QString getDataBaseName();

private slots:
    void on_DB_pushButton_commit_clicked();

private:
    Ui::DBLogin *ui;

    QSqlDatabase *DBpointer;
    QSettings *iniPointer;
    //初始化登錄窗口
    void initLoginWindow();
    //登錄函數
    bool login();
    //讀取配置文件
    void readINIFile();
    void updateINIFile();
};

#endif // DBLOGIN_H

dblogin.cpp

#include "dblogin.h"
#include "ui_dblogin.h"

DBLogin::DBLogin(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::DBLogin)
{
    ui->setupUi(this);
    DBpointer=(new DataBases())->getDataBasePointer();
    initLoginWindow();
}

DBLogin::~DBLogin()
{
    delete ui;
}

QString DBLogin::getUserName()
{
    QString userName=ui->DB_LineEdit_username->text();
    iniPointer->setValue("USERNAME/username",userName);
    return userName;
}

QString DBLogin::getPassWord()
{
    QString passWord= ui->DB_lineEdit_password->text();
    iniPointer->setValue("PASSWORD/password",passWord);
    return passWord;
}

QString DBLogin::getHostName()
{
    QString hostName=ui->DB_lineEdit_hostname->text();
    iniPointer->setValue("HOSTNAME/hostname",hostName);
    return hostName;
}

QString DBLogin::getPort()
{
    QString port=ui->DB_lineEdit_port->text();
    iniPointer->setValue("PORT/port",port);
    return port;
}

QString DBLogin::getDataBaseName()
{
    DataBases::DataBasesName=ui->DB_lineEdit_DBname->text();
    iniPointer->setValue("DATABASESNAME/databasesname",DataBases::DataBasesName);
    return DataBases::DataBasesName;
}

void DBLogin::on_DB_pushButton_commit_clicked()
{
    if(login()==false)
    {
        QDialog::done(LOGINFAILURE);
    }
    else
    {
        QDialog::done(LOGINSUCCESS);
    }

}

void DBLogin::initLoginWindow()
{
    setWindowTitle("數據庫管理工具登錄窗口");
    ui->DB_lineEdit_password->setEchoMode(QLineEdit::PasswordEchoOnEdit);
    readINIFile();
}

bool DBLogin::login()
{
    DBpointer->setHostName(getHostName());
    DBpointer->setPort(getPort().toInt());
    DBpointer->setUserName(getUserName());
    DBpointer->setPassword(getPassWord());
    DBpointer->setDatabaseName(getDataBaseName());
    return DBpointer->open();
}

void DBLogin::readINIFile()
{
    QString fileName="DataBases.ini";
    //讀取配置文件
    iniPointer=new QSettings(fileName,QSettings::IniFormat);
    ui->DB_lineEdit_hostname->setText(iniPointer->value("HOSTNAME/hostname").toString());
    ui->DB_LineEdit_username->setText(iniPointer->value("USERNAME/username").toString());
    ui->DB_lineEdit_port->setText(iniPointer->value("PORT/port").toString());
    ui->DB_lineEdit_password->setText(iniPointer->value("PASSWORD/password").toString());
    ui->DB_lineEdit_DBname->setText(iniPointer->value("DATABASESNAME/databasesname").toString());
}

main.cpp

#include "databases.h"
#include "dblogin.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    DataBases dataBases;
    DBLogin login;
    if(login.exec()==LOGINSUCCESS)
    {
        dataBases.initWindow();
        dataBases.show();
    }
    else
    {
        qDebug()<< dataBases.getDataBasePointer()->lastError().text()<<endl;
    }
    return a.exec();
}