本文记录使用QSqlTableModel等组件实现单表的数据库操作。
QSqlTableModel是一个模型类，它的实例可以作为一个数据表的模型。使用QSqlTableModel模型和QTableView组件构成模型/视图结构，就可以实现数据表的数据显示和编辑。
目录
所需的类及定义
表格控件设置QTableView
打开数据库连接db.open()
表设置初始化、表查询
设置表名
设置表排序字段
打开表-查询
显示行数
设置表格的水平字段标题
创建选择模型
绑定数据模型 和 选择模型
绑定之后，将图片列和备注列在表格中不显示
绑定自定义下拉框到部门列、性别列
创建界面组件与数据模型字段之间的数据映射
定义数据映射组件
设置界面组件和模型字段之间的映射
移动到首记录，将首行的记录赋值给绑定的控件
表插入
表追加一行
表操作撤销
表操作提交
表记录删除
表排序切换
表条件过滤及过滤条件清空
逐行修改数据并提交
BLOB字段的保存、清空、显示图片
表事件处理
单元格值发生变化处理事件
焦点行发生变换
表其他操作
获取水平列名
所需的类及定义
| 解释 | 类 |
| 数据库连接 | QSqlDatabase |
| 显示控件 | QTableView |
| Model视图 | QSqlTableModel |
| 选择Model | QItemSelectionModel |
| 字段编辑绑定 | QDataWidgetMapper |
| 自定义combox代理控件 | TComboBoxDelegate |
| 性别字符列表 | genderList |
| 部门字符列表 | deptList |
| 省份字符列表 | provinceList |
QSqlDatabase DB;QSqlTableModel *tabModel;QItemSelectionModel *selModel;QDataWidgetMapper *dataMapper;//数据映射TComboBoxDelegate delegateSex;TComboBoxDelegate delegateDept;QStringList genderList;QStringList deptList;QStringList provinceList;表格控件设置QTableView
行背景交替颜色、单个单元格选择模式
ui->tableView->setSelectionBehavior(QAbstractItemView::SelectItems);ui->tableView->setSelectionMode(QAbstractItemView::SingleSelection);ui->tableView->setAlternatingRowColors(true);打开数据库连接db.open()
打开SQLite数据库
bool SqlTableModelExample::openDataBase(QString aFile)
{DB = QSqlDatabase::addDatabase("QSQLITE");//添加SQLite驱动DB.setDatabaseName(aFile);//设置数据库名称if(!DB.open())//打开数据库{QMessageBox::warning(this, "错误", "打开数据库失败");return false;}else{openTable();return true;}
}表设置初始化、表查询
设置表名
tabModel = new QSqlTableModel(this,DB);
tabModel->setTable("employee");设置表排序字段
tabModel->setSort(tabModel->fieldIndex("empNo"),Qt::AscendingOrder);打开表-查询
if(!tabModel->select()){//MessageBoxHelper::critical(this,"打开数据表错误，错误信息：\n"+tabModel->lastError().text());QMessageBox::critical(this,"错误信息","打开数据表错误，错误信息：\n"+tabModel->lastError().text());return;}显示行数
void SqlTableModelExample::showRecordCount()
{ui->statusbar->showMessage(QString("记录条数：%1").arg(tabModel->rowCount()));
}设置表格的水平字段标题
tabModel->setHeaderData(tabModel->fieldIndex("empNo"),Qt::Horizontal,"工号");tabModel->setHeaderData(tabModel->fieldIndex("Name"),Qt::Horizontal,"姓名");tabModel->setHeaderData(tabModel->fieldIndex("Gender"),Qt::Horizontal,"性别");tabModel->setHeaderData(tabModel->fieldIndex("Birthday"),Qt::Horizontal,"出生日期");tabModel->setHeaderData(tabModel->fieldIndex("Province"),Qt::Horizontal,"省份");tabModel->setHeaderData(tabModel->fieldIndex("Department"),Qt::Horizontal,"部门");tabModel->setHeaderData(tabModel->fieldIndex("Salary"),Qt::Horizontal,"薪水");//不在列表tabView中显示tabModel->setHeaderData(tabModel->fieldIndex("Memo"),Qt::Horizontal,"备注");tabModel->setHeaderData(tabModel->fieldIndex("Photo"),Qt::Horizontal,"照片");创建选择模型
selModel = new QItemSelectionModel(tabModel,this);
将选择模型的单元格值变化事件、行变化/切换 绑定到处理方法
如单元格值发生变化，将保存、撤销操作按钮变亮；行切换时，绑定的显示控件显示对应行的值
connect(selModel,&QItemSelectionModel::currentChanged,this,&SqlTableModelExample::do_currentChanged);connect(selModel,&QItemSelectionModel::currentRowChanged,this,&SqlTableModelExample::do_currentRowChanged);绑定数据模型 和 选择模型
ui->tableView->setModel(tabModel);ui->tableView->setSelectionModel(selModel);绑定之后，将图片列和备注列在表格中不显示
ui->tableView->setColumnHidden(tabModel->fieldIndex("Memo"),true);ui->tableView->setColumnHidden(tabModel->fieldIndex("Photo"),true);绑定自定义下拉框到部门列、性别列
bool isEditable = false;delegateSex.setItems(genderList,isEditable);ui->tableView->setItemDelegateForColumn(tabModel->fieldIndex("Gender"),&delegateSex);isEditable = true;delegateDept.setItems(deptList,isEditable);ui->tableView->setItemDelegateForColumn(tabModel->fieldIndex("Department"),&delegateDept);创建界面组件与数据模型字段之间的数据映射
定义数据映射组件
dataMapper = new QDataWidgetMapper(this);dataMapper->setModel(tabModel);dataMapper->setModel(tabModel); dataMapper->setSubmitPolicy(QDataWidgetMapper::AutoSubmit); //自动提交设置界面组件和模型字段之间的映射
dataMapper->addMapping(ui->dbSpinEmpNo,tabModel->fieldIndex("empNo"));dataMapper->addMapping(ui->dbEditName,tabModel->fieldIndex("Name"));dataMapper->addMapping(ui->dbComboSex,tabModel->fieldIndex("Gender"));dataMapper->addMapping(ui->dbEditBirth,tabModel->fieldIndex("Birthday"));dataMapper->addMapping(ui->dbComboProvince,tabModel->fieldIndex("Province"));dataMapper->addMapping(ui->dbComboDept,tabModel->fieldIndex("Department"));dataMapper->addMapping(ui->dbSpinSalary,tabModel->fieldIndex("Salary"));dataMapper->addMapping(ui->dbEditMemo,tabModel->fieldIndex("Memo"));
移动到首记录，将首行的记录赋值给绑定的控件
dataMapper->toFirst();表插入
void SqlTableModelExample::on_actRecInsert_triggered()
{QModelIndex curIndex = ui->tableView->currentIndex();QSqlRecord rec = tabModel->record();//获取一个空记录，只有字段定义tabModel->insertRecord(curIndex.row(),rec);selModel->clearSelection();selModel->setCurrentIndex(curIndex,QItemSelectionModel::Select);showRecordCount();
}
表追加一行
void SqlTableModelExample::on_actRecAppend_triggered()
{QSqlRecord rec = tabModel->record();//获取一个空记录rec.setValue(tabModel->fieldIndex("empNo"),2000+tabModel->rowCount());rec.setValue(tabModel->fieldIndex("Gender"),"男");tabModel->insertRecord(tabModel->rowCount(),rec);//插入到数据模型的最后selModel->clearSelection();QModelIndex curIndex = tabModel->index(tabModel->rowCount()-1,1);selModel->setCurrentIndex(curIndex,QItemSelectionModel::Select);showRecordCount();
}表操作撤销
void SqlTableModelExample::on_actRevert_triggered()
{tabModel->revertAll();ui->actSubmit->setEnabled(false);ui->actRevert->setEnabled(false);showRecordCount();
}表操作提交
void SqlTableModelExample::on_actSubmit_triggered()
{bool res = tabModel->submitAll();if(!res){QMessageBox::critical(this,"错误提示","数据保存错误，错误信息："+tabModel->lastError().text());return;}else{ui->actSubmit->setEnabled(false);ui->actRevert->setEnabled(false);}showRecordCount();
}表记录删除
void SqlTableModelExample::on_actRecDelete_triggered()
{QModelIndex curIndex = selModel->currentIndex();tabModel->removeRow(curIndex.row());showRecordCount();
}表排序切换
void SqlTableModelExample::on_radioBtnDescend_clicked()
{tabModel->setSort(ui->comboFields->currentIndex(),Qt::DescendingOrder);//tabModel->setSort(ui->comboFields->currentIndex(),Qt::AscendingOrder);tabModel->select();//执行刷新 才会显示排序
}//切换成别的字段排序
void SqlTableModelExample::on_comboFields_currentIndexChanged(int index)
{if(ui->radioBtnAescend->isChecked())tabModel->setSort(index,Qt::AscendingOrder);elsetabModel->setSort(index,Qt::DescendingOrder);tabModel->select();
}
表条件过滤及过滤条件清空
void SqlTableModelExample::on_radioBtnMan_clicked()
{tabModel->setFilter(" Gender='男");showRecordCount();
}void SqlTableModelExample::on_radioBtnBoth_clicked()
{tabModel->setFilter("");showRecordCount();
}逐行修改数据并提交
void SqlTableModelExample::on_actScan_triggered()
{if(tabModel->rowCount()==0)return;for(int i=0;i<tabModel->rowCount();i++){QSqlRecord rec = tabModel->record(i);float salary = rec.value("Salary").toFloat();rec.setValue("Salary",salary*1.1);tabModel->setRecord(i,rec);}if(tabModel->submitAll())QMessageBox::information(this,"提示","计算完毕");
}BLOB字段的保存、清空、显示图片
void SqlTableModelExample::on_actPhoto_triggered()
{QString aFile = QFileDialog::getOpenFileName(this,"选择图片文件","","照片(*.jpg)");if(aFile.isEmpty())return;QByteArray data;QFile *file = new QFile(aFile);file->open(QIODevice::ReadOnly);data = file->readAll();file->close();delete file;int curRecNo = selModel->currentIndex().row();QSqlRecord curRec= tabModel->record(curRecNo);curRec.setValue("Photo",data);tabModel->setRecord(curRecNo,curRec);QPixmap pic;pic.load(aFile);ui->dbLabPhoto->setPixmap(pic.scaledToWidth(ui->dbLabPhoto->size().width()));;
}
通过tableModel.SubmitAll() 提交
表事件处理
单元格值发生变化处理事件
判断是否更改 isDirty()方法
//数据发生更改的时候，更新actPost 和 actCancel的状态
void SqlTableModelExample::do_currentChanged(const QModelIndex ¤t, const QModelIndex &previous)
{Q_UNUSED(current);Q_UNUSED(previous);ui->actSubmit->setEnabled(tabModel->isDirty());ui->actRevert->setEnabled(tabModel->isDirty());
}焦点行发生变换
切换dataMapper
void SqlTableModelExample::do_currentRowChanged(const QModelIndex ¤t, const QModelIndex &previous)
{Q_UNUSED(previous);ui->actRecDelete->setEnabled(current.isValid());ui->actPhoto->setEnabled(current.isValid());ui->actPhotoClear->setEnabled(current.isValid());if(!current.isValid()){ui->dbLabPhoto->clear();return;}int curRecNo = current.row();dataMapper->setCurrentIndex(curRecNo);QSqlRecord curRec = tabModel->record(curRecNo);//获取当前记录if(curRec.isNull("Photo"))ui->dbLabPhoto->clear();else{QByteArray data =curRec.value("Photo").toByteArray();QPixmap pic;pic.loadFromData(data);ui->dbLabPhoto->setPixmap(pic.scaledToWidth(ui->dbLabPhoto->size().width()));}
}表其他操作
获取水平列名
void SqlTableModelExample::getFieldNames()
{QSqlRecord emptyRec = tabModel->record();for(int i=0;i<emptyRec.count();i++){qDebug()<<emptyRec.count();ui->comboFields->addItem(emptyRec.fieldName(i));}
}
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