1 //main.cpp
2 #include "mywin.h"
3 #include "foodtype.h"
4 #include <QApplication>
5 #include <QSqlDatabase>
6 #include <QDebug>
7 #include <QSqlDriver>
8 #include <QSqlQuery>
9 #include <QMessageBox>
10 int main(int argc, char *argv[])
11 {
12 QApplication a(argc, argv);
13 // QSqlDatabase db;
14 QSqlDatabase db=QSqlDatabase::addDatabase("QMYSQL");//数据库必须在声明的时候指定，否则会出错
15 qDebug()<< db.drivers();//查看支持的数据库
16 //db.addDatabase("QMYSQL");
17 db.setDatabaseName("mydb");
18 db.setHostName("192.168.2.90");
19 db.setUserName("who");
20 db.setPassword("123456");
21 if(!db.open())
22 {
23 QMessageBox::critical(0,"error","open databases failed");
24 exit(0);
25 }
26 qDebug()<<db.tables();
27
28
29 QSqlQuery query;
30 query.exec("select *from foodtype;");
31 while(query.next())
32 {
33 qDebug()<<query.value(0).toInt();//转化一下，要不会把数据类型一块打印出来
34 qDebug()<<query.value(1).toString();
35 }
36
37 qDebug()<<query.exec("show tables;");
38 MyWin w;
39 w.show();
40
41 FoodType foodtype;
42 foodtype.show();
43 return a.exec();
44 }
1 //mywin.cpp
2 #include "mywin.h"
3 #include "ui_mywin.h"
4 #include <QSqlQuery>
5 #include <QDebug>
6 #include <QMessageBox>
7 #include <QString>
8
9 MyWin::MyWin(QWidget *parent) :
10 QWidget(parent),
11 ui(new Ui::MyWin)
12 {
13 ui->setupUi(this);
14
15 QSqlQuery query;
16 query.exec("select *from foodtype;");
17 while(query.next())
18 {
19 // ui->comboBox->addItem(query.value(0).toInt(),query.value(1).toString());//将菜系添加到下拉列表中,必须在后面加上为数据项
20 //，要不后面无法获取fid的下标；
21 ui->comboBox->addItem(query.value(1).toString(),query.value(0).toInt());
22 }
23 }
24
25 MyWin::~MyWin()
26 {
27 delete ui;
28 }
29
30 void MyWin::on_pushButton_2_clicked()
31 {
32 this->close();
33 }
34
35 void MyWin::on_pushButton_clicked()
36 {
37 QSqlQuery query;
38 int fid=ui->comboBox->currentData().toInt();//获取下拉列表里的数据值
39 //qDebug()<<fid;
40 if(ui->line_id->text().isEmpty())
41 {
42 QMessageBox::critical(this,"error","please input id");
43 ui->line_id->setFocus();//聚焦光标
44 return;//exit current function
45 }
46
47 if(ui->line_name->text().isEmpty())
48 {
49 QMessageBox::critical(this,"error","please input name");
50 ui->line_name->setFocus();//聚焦光标
51 return;
52 }
53 if(ui->line_price->text().isEmpty())
54 {
55 QMessageBox::critical(this,"error","please input price");
56 ui->line_price->setFocus();//聚焦光标
57 return;
58 }
59 //int id=ui->line_id->text().toInt(); //用Qstring 类型声明id，要不下面打印id号时会报错
60 QString id=ui->line_id->text();
61 QString str2("select *from food where fid=%1;");
62 qDebug()<< query.exec(str2.arg(id));
63 while(query.next())
64 {
65 QMessageBox::critical(this,"error","id" + id + "used");
66 ui->line_id->setFocus();
67 return;
68 }
69
70 QMessageBox mesgBox(this);
71 mesgBox.setText("The document has been modified.");
72 mesgBox.setInformativeText("Do you want to save you change?");
73 mesgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Cancel |QMessageBox::Discard);
74 int ret=mesgBox.exec();
75
76 QString name=ui->line_name->text();
77 float price=ui->line_price->text().toFloat();
78 QString mem =ui->textEdit->document()->toPlainText();//多行编辑的显示
79
80 QString str("insert into food values(%1,'%2',%3,%4,'%5');");
81 switch(ret){
82 case QMessageBox::Save:
83 query.exec(str.arg(id).arg(name).arg(fid).arg(price).arg(mem));
84 break;
85 case QMessageBox::Cancel:
86 // return;
87 break;
88 case QMessageBox::Discard:
89 ui->line_id->setText(" ");
90 return;
91 break;
92 }
93 }
1 //显示tableview里的数据时，要用到《QsqlQueryModel》,
#include "ui_foodtype.h"
2 //#include <QSqlTableModel>
3 #include <QSqlQueryModel>
4
5 FoodType::FoodType(QWidget *parent) :
6 QWidget(parent),
7 ui(new Ui::FoodType)
8 {
9 ui->setupUi(this);
10 QSqlQueryModel *model=new QSqlQueryModel(this);
11 // model->setTable("菜单信息");
12 model->setQuery("select fid,food.name,ftypeid,fprice,id,foodtype.name,mem from food inner join foodtype on id=fid;");
13
14 ui->tableView->setModel(model);
15 }
16
17 FoodType::~FoodType()
18 {
19 delete ui;
20 }
