qt实现sqlite3的级联删除

概述1.需求 有两张表，条码表和产品详情表，条码表中的rfid为产品表中的rfid外键，要求删除产品表中的相关条目时能实现条码表的级联删除 2.解决 使用qt中的sqlite3自带的级联删除解决这个需求 3.代码 mymain.cpp #include "mysql.h"#include <QtWidgets/QApplication>#include <QSqlDatabase>#includ 1.需求 有两张表，条码表和产品详情表，条码表中的rfID为产品表中的rfID外键，要求删除产品表中的相关条目时能实现条码表的级联删除 2.解决 使用qt中的sqlite3自带的级联删除解决这个需求 3.代码 mymain.cpp

#include "MysqL.h"#include <QtWidgets/QApplication>#include <QsqlDatabase>#include <QsqlError>#include <Qsqlquery>#include <QtCore/QDir>#include <QMessageBox>bool createdb();int main(int argc,char *argv[]){    QApplication a(argc,argv);    createdb();    MysqL w;    w.show();    return a.exec();}bool createdb(){    bool bret = false;    //这里创建一个db目录存储数据库文件    QString strdbpath("");    strdbpath = QCoreApplication::applicationDirPath();    strdbpath += "/db";    QDir dir("");    dir.mkpath(strdbpath);    strdbpath += "/MysqLite.db";    QsqlDatabase dbset = QsqlDatabase::addDatabase("QsqlITE","file");    dbset.setDatabasename(strdbpath);    if (!dbset.open()) {        //LOG_ALL_ERROR(QStringliteral("Failed open MysqLite.db"));        return bret;    }     Qsqlquery setquery(QsqlDatabase::database("file",true));     if(!setquery.exec("PRAGMA foreign_keys = ON;"))     {         QsqlError sqlerror = setquery.lastError();         QString texterr = sqlerror.text();         QMessageBox::information(nullptr,"errormsg",texterr);         return false;     }    //商品详情表    bret = setquery.exec("create table tb_goods(rfID varchar(33) primary key,name varchar(200) not null)");    if (!bret)    {        QsqlError sqlerror = setquery.lastError();        QString texterr = sqlerror.text();        if (texterr.contains("already exists",Qt::CaseInsensitive))            bret = true;        else        {            //LOG_ALL_ERROR(QStringliteral("Failed create table tb_goods."));            return bret;        }    }    //这里条码对照表和skuID对照表因为可能牵涉到多对多的情况 故没有作为主键    //条码对照表    bret = setquery.exec("create table tb_barcode(ID INTEGER PRIMARY KEY autoINCREMENT,"                         "barcode varchar(100) not null,rfID varchar(33) not null,"                         "FOREIGN KEY(rfID) REFERENCES tb_goods(rfID) ON DELETE cascade)");    if (!bret)    {        QsqlError sqlerror = setquery.lastError();        QString texterr = sqlerror.text();        if (texterr.contains("already exists",Qt::CaseInsensitive))            bret = true;        else        {            return bret;        }    }    return bret;}

MysqL.h

#ifndef MysqL_H#define MysqL_H#include <QtWidgets/QMainWindow>#include <QsqlqueryModel>#include "ui_MysqL.h"class MysqL : public QMainWindow{    Q_OBJECTpublic:    MysqL(QWidget *parent = 0);    ~MysqL();private slots:    voID on_insertbutton_clicked();    voID on_deletebutton_clicked();    voID on_updatebutton_clicked();private:    voID reflushModel();    voID setAttibutes(QtableVIEw* pVIEw,int nheaderHeight = 45,int nColumnHeight = 45);private:    Ui::MysqLClass ui;    QsqlqueryModel m_goodsmodel;    QsqlqueryModel m_barcodemodel;};#endif // MysqL_H

MysqL.cpp

#include "MysqL.h"#include <QsqlError>#include <Qsqlquery>#include <QScrollbar>MysqL::MysqL(QWidget *parent)    : QMainWindow(parent){    ui.setupUi(this);    m_goodsmodel.setquery("select * from tb_goods",QsqlDatabase::database("file",true));    m_goodsmodel.setheaderData(0,Qt::Horizontal,QStringliteral("ID"));    m_goodsmodel.setheaderData(1,QStringliteral("名称"));    m_barcodemodel.setquery("select * from tb_barcode",true));    m_barcodemodel.setheaderData(0,QStringliteral("ID"));    m_barcodemodel.setheaderData(1,QStringliteral("扫描码"));    m_barcodemodel.setheaderData(2,QStringliteral("rfID"));    ui.goodVIEw->setModel(&m_goodsmodel);    ui.skuIDVIEw->setModel(&m_barcodemodel);    setAttibutes(ui.goodVIEw);    setAttibutes(ui.skuIDVIEw);}MysqL::~MysqL(){}voID MysqL::on_insertbutton_clicked(){    Qsqlquery setquery(QsqlDatabase::database("file",true));    setquery.exec("insert into tb_goods values('123456789','aaa')");    setquery.exec("insert into tb_goods values('23456789','aaeffdda')");    setquery.exec("insert into tb_barcode(barcode,rfID) values('adddaeee','123456789')");    reflushModel();}//这里应该问题不是很大voID MysqL::on_deletebutton_clicked(){    Qsqlquery setquery(QsqlDatabase::database("file",true));    setquery.exec("delete from tb_goods where rfID='123456789'");    reflushModel();}voID MysqL::on_updatebutton_clicked(){    Qsqlquery setquery(QsqlDatabase::database("file",true));    setquery.exec("update tb_goods set name='redddd' where rfID='123456789'");    reflushModel();}voID MysqL::reflushModel(){    m_goodsmodel.setquery("select * from tb_goods",true));    m_barcodemodel.setquery("select * from tb_barcode",true));}voID MysqL::setAttibutes(QtableVIEw* pVIEw,int nheaderHeight,int nColumnHeight){    if ( pVIEw == NulL )    {        QString strTemp = QStringliteral("pVIEw== NulL！设置表格属性失败！");        return;    }    pVIEw->horizontalheader()->setFixedHeight(nheaderHeight);               //设置表头的高度    pVIEw->horizontalheader()->setSectionsClickable(false);                 //设置表头不可点击（默认点击后进行排序）    pVIEw->horizontalheader()->setStretchLastSection(true);                 //最后一列占满剩余空白    pVIEw->setSelectionBehavior(QAbstractItemVIEw::SelectRows);             //设置选择行为时每次选择一行        pVIEw->setEditTriggers(QAbstractItemVIEw::NoEditTriggers);              //使表视图只读        pVIEw->verticalheader()->setDefaultSectionSize(nColumnHeight);          //设置行高    pVIEw->setAlternatingRowcolors(true);                                   //可以交替颜色显示    pVIEw->setShowGrID(false);                                              //设置不显示格子线    pVIEw->setCornerbuttonEnabled(false);                                   //左上角的按钮不可用，此按钮功能，一点击，全选    pVIEw->horizontalScrollbar()->setStyleSheet(        "QScrollbar:horizontal{height:10px;background:transparent;background-color:rgb(248,248,248);margin:0px,0px,0px;padding-left:10px;padding-right:10px;}"        "QScrollbar::handle:horizontal{height:10px;background:lightgray;border-radius:5px;/*min-height:20;*/}"        "QScrollbar::handle:horizontal:hover{height:10px;background:gray;border-radius:5px;/*min-height:20;*/}"        "QScrollbar::add-line:horizontal{/*height:10px;wIDth:10px;*/border-image:url(:/button/images/button/right.png);/*subcontrol-position:right;*/}"        "QScrollbar::sub-line:horizontal{/*height:10px;wIDth:10px;*/border-image:url(:/button/images/button/left.png);/*subcontrol-position:left;*/}"        "QScrollbar::add-line:horizontal:hover{/*height:10px;wIDth:10px;*/border-image:url(:/button/images/button/right_mouseDown.png);/*subcontrol-position:right;*/}"        "QScrollbar::sub-line:horizontal:hover{/*height:10px;wIDth:10px;*/border-image:url(:/button/images/button/left_mouseDown.png);/*subcontrol-position:left;*/}"        "QScrollbar::add-page:horizontal,QScrollbar::sub-page:horizontal{background:transparent;border-radius:5px;}"        );    pVIEw->verticalScrollbar()->setStyleSheet(        "QScrollbar:vertical{wIDth:10px;background:transparent;background-color:rgb(248,0px;padding-top:10px;padding-bottom:10px;}"        "QScrollbar::handle:vertical{wIDth:10px;background:lightgray ;border-radius:5px;min-height:20;}"        "QScrollbar::handle:vertical:hover{wIDth:10px;background:gray;border-radius:5px;min-height:20;}"        "QScrollbar::add-line:vertical{height:10px;wIDth:10px;border-image:url(:/button/images/button/down.png);subcontrol-position:bottom;}"        "QScrollbar::sub-line:vertical{height:10px;wIDth:10px;border-image:url(:/button/images/button/up.png);subcontrol-position:top;}"        "QScrollbar::add-line:vertical:hover{height:10px;wIDth:10px;border-image:url(:/button/images/button/down_mouseDown.png);subcontrol-position:bottom;}"        "QScrollbar::sub-line:vertical:hover{height:10px;wIDth:10px;border-image:url(:/button/images/button/up_mouseDown.png);subcontrol-position:top;}"        "QScrollbar::add-page:vertical,QScrollbar::sub-page:vertical{background:transparent;border-radius:5px;}"        );}

4.备注 1.完整的代码下载http://download.csdn.net/detail/zhang_ruiqiang/8939977 2.还存在的问题使用自带的自增作为主键可能会出现越界的问题，不过integer最大为9223372036854775807如果数据量不是很大的话可以不必考虑 3.在vs2010+qt 5.40 + win7下编译通过 4.参考http://bbs.csdn.net/topics/391065975 总结

以上是内存溢出为你收集整理的qt实现sqlite3的级联删除全部内容，希望文章能够帮你解决qt实现sqlite3的级联删除所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。