SQLite+Qt 图书管理系统设计（具体实现）

https://github.com/birdy-C/BookSystem.git

详细设计

SQLite是一款轻型的数据库，占用资源低，与Qt的连接便易。

数据库逻辑结构设计

创建

PRAGMA foreign_keys = ON;   ----------------------------------------------------------------------------------------------- create table type( Book_type nvarchar(10)        primary key         , Type_number     int     NOT NULL UNIQUE ,  check (Type_number  >0)        ); ---------------------------------------------------------------------------------------------- create table book( Book_ID    int     primary key         , Type  nvarchar(10)        REFERENCES type(Book_type)   , Title  nvarchar              , Publisher    nvarchar              , Publish_year       int     check(publish_year>1800 )   , Author       NVARCHAR               , Price decimal(6,2)                  , Number      int     check(Number>=0)      , Stocks        int     check(Stocks>=0)        ); --------------------------临时表，处理批量入库------------------------------------- create table book_temp( Type  nvarchar(10)        , Title  nvarchar              , Publisher    nvarchar              , Publish_year       int     , Author       NVARCHAR               , Price decimal(6,2)                  , Number      int     ); ------------------------------------------------------------------------------------------------ create table library_card( card_ID      int     primary key         , Username   varchar(10)          , Company   nvarchar              , Type  varchar(10) check (Type in ( 'student', 'teacher' ) )); ----------------------------------------------------------------------------------------------- create table manager( manager_ID        int     primary key         , Password   varchar(10) not null       , Name         varchar(10)          , Connection int               ); ----------------------------------------------------------------------------------------------- create table record ( Book_ID    int     REFERENCES book(Book_ID)    , card_ID      int     REFERENCES Library_card(card_ID) , borrow_data        data            , return_data data   check ( return_data >= borrow_data )      , manager_ID        int     REFERENCES manager(manager_ID)    , primary key(Book_ID,card_ID) );

 

 

 

触发器

--------------检查出版年份-----------------   CREATE TRIGGER Tr_check_date AFTER insert ON book FOR EACH ROW WHEN( (select Book_ID from book where publish_year > (SELECT strftime('%Y',date('now')) ) )is not null) BEGIN SELECT RAISE(ROLLBACK, 'IMPOSSIBLE DATE') ; END;   --------------检查输入时 库存与数量是否相等-----------------     CREATE TRIGGER Tr_check_number BEFORE insert ON book FOR EACH ROW WHEN    ( new.Number <> new.Stocks ) BEGIN   SELECT RAISE(ROLLBACK, 'ANY WRONG ABOUT NUMBER?');   END;   --------------借出检查是否有余量----------------- CREATE TRIGGER Tr_borrow_check BEFORE insert ON record FOR EACH ROW WHEN 0=(select Stocks from book where Book_ID=new.Book_ID) BEGIN   SELECT RAISE(ROLLBACK, 'NO REMAINING') ; END;     --------------借出检查借书证 老师5学生3----------------- CREATE TRIGGER Tr_borrow_card AFTER insert ON record FOR EACH ROW WHEN ( (select count(*) from record join          (select card_ID as S from library_card          where card_ID = new.card_ID and Type = 'student')          on          record.card_ID = S          ) >3   --学生 or (select count(*) from record join          (select card_ID as T from library_card          where card_ID = new.card_ID and Type = 'teacher')          on          record.card_ID = T          ) >5   --老师   ) BEGIN      SELECT RAISE(ROLLBACK, 'MORE THAN PERMITTED') ; END;   --------------借出更新数据----------------- CREATE TRIGGER Tr_borrow AFTER insert ON record FOR EACH ROW BEGIN   UPDATE Book   SET Stocks = (                    select         Stocks - 1                    FROM Book                    WHERE                     Book_ID = new.Book_ID                    )   WHERE   Book_ID = new.Book_ID ; END;   --------------返回更新数据-----------------   CREATE TRIGGER Tr_return AFTER delete ON record FOR EACH ROW BEGIN   UPDATE Book   SET Stocks = (                    select         Stocks + 1                    FROM Book                    WHERE                     Book_ID = old.Book_ID                    )   WHERE   Book_ID = old.Book_ID ; END;   --------------插入检查是否已经存在----------------- ---------这一段大概有很多可以优化的地方吧……   CREATE TRIGGER Tr_check_insert AFTER insert ON book FOR EACH ROW WHEN (          (          select count(Book_ID)  from book          where Type = new.Type and Title = new.Title and Publisher = new.Publisher                    and Publish_year = new.Publish_year and Author = new.Author and Price = new.Price          )          >1--except for new ) BEGIN UPDATE Book     SET Stocks = (                    select         Stocks + new.Stocks                    FROM Book                    where Type = new.Type and Title = new.Title and Publisher = new.Publisher                             and Publish_year = new.Publish_year and Author = new.Author and Price = new.Price                      )          where Type = new.Type and Title = new.Title and Publisher = new.Publisher                    and Publish_year = new.Publish_year and Author = new.Author and Price = new.Price; UPDATE Book     SET Number = (                    select         Number + new.Number                    FROM Book                    where Type = new.Type and Title = new.Title and Publisher = new.Publisher                             and Publish_year = new.Publish_year and Author = new.Author and Price = new.Price                    )     where Type = new.Type and Title = new.Title and Publisher = new.Publisher                    and Publish_year = new.Publish_year and Author = new.Author and Price = new.Price;            DELETE FROM Book     WHERE Book_ID = new.Book_ID; END;

 

图书管理系统设计

一、主要类说明（SQL相关）以及主要使用

 

QsqlDatabase提供了一个Qt和DB的连接口。

以下代码为数据库连接代码，并且打开数据库文件DBSYSTEN.db

/*---- LOAD IN DASTABASE ----*/     db = QSqlDatabase::addDatabase("QSQLITE");     db.setDatabaseName("DBSYSTEM.db");     if (!db.open()) {         QMessageBox::warning(0, QObject::tr("Database Error"),db.lastError().text());         qDebug() << QString("LOAD_IN");         returnfalse;     }

此外可以通过boolQSqlDatabase::transaction(),bool QSqlDatabase::commit()，bool QSqlDatabase::rollback()来实现相当于撤销和保存的操作。

 

QsqlQuery提供了一个SQL语句的运行接口。

如下面语句，实现的是读取Book_id对应书的库存和数量。

QSqlQuery query_getStocks("select Stocks,Number from book where Book_id = '"+ ID +"'");     int Stocks_int, All_int;     if (query_getStocks.next())     {         Stocks_int = query_getStocks.value(0).toInt();         All_int = query_getStocks.value(1).toInt();     }     else     {         QMessageBox::warning(0,QObject::tr("INACCURACY DATA"),"Please check the ID");         return;     }

 

QsqlError提供SQL数据库的错误信息。

在这里主要用于处理QSqlError QSqlDatabase::lastError()const返回的错误。

 

 QSqlTableModel 可以很方便地为一个table（或者view）提供可编辑的形式。

在ui界面上显示table book的代码如下：

select_model = newQSqlTableModel(this);     select_model->setTable("book");     ui.tableView_select->setModel(select_model);     select_model->select();     ui.tableView_select->setEditTriggers(QAbstractItemView::NoEditTriggers);//不可编辑     ui.tableView_select->setSelectionBehavior(QAbstractItemView::SelectRows);//整行选中

 

 

QSqlRecord读取数据库记录。

下为读取临时table book_temp中的代码插入book中（SL_insert_book为插入的函数）的代码。

for (int i = select_model_insert2->rowCount()-1; i >= 0; i--)     {         QSqlRecord record = select_model_insert2->record(i);         bool ok;         ok = SL_insert_book         (             record.value("Type").toString(),             record.value("Title").toString(),             record.value("Publisher").toString(),             record.value("Publish_year").toString(),             record.value("Author").toString(),             record.value("Price").toString(),             record.value("Number").toString()         );         if(ok)         {             select_model_insert2->removeRow(i);         }           }

 

 

QModelIndex这里用来处理读取QSqlTableModel的选中数据。

读取选中的数据类型，并依次修改ui.lineEdit_8的数据，代码如下：

voidBookSystem::SL_insert1_selectType(constQModelIndex &, constQModelIndex &) {     QModelIndex index=ui.tableView_insert1_type->currentIndex();     QModelIndex i1 = index.sibling(index.row(), 0);     QString str1 = i1.data().toString();     ui.lineEdit_8->setText(str1); }

 

 

二、主要类说明（界面相关）

控件	信号
tabWidget	currentChanged(int)
lineEdit	textEdited(const QString &)
pushButton	clicked()
checkBox	released()
radioButton	released()
spinBox	valueChanged(int)
doubleSpinBox	valueChanged(double)
tableView->selectionModel()	currentRowChanged(const QModelIndex &,const QModelIndex &)

 

三、具体实现及主要界面

1.管理员登陆

检查用户是否存在

boolBookSystem:: checkManager() {     QSqlQuery query_temp("select manager_ID, Name from manager where manager_ID = '"+ ui.lineEdit_18->text()         +"'AND Password = '"+ ui.lineEdit_17->text()+"';");       if (query_temp.next())     {         manager_ID = query_temp.value(0).toInt();         manager_name = query_temp.value(1).toString();       }     else     {         QMessageBox::warning(0,QObject::tr("NO SUCH INFORMATION"),"make sure you add the accurate information");         returnfalse;     }     returntrue; }

 

更新界面

voidBookSystem::SL_user_loadin() {     if (false == checkManager())     {         ui.lineEdit_17->setText("");         return;     }       QMessageBox::about(0,QObject::tr("LOAD IN"),"Welcome ! "+ manager_name+".");       load_statues = true;     //manager_ID = ui.lineEdit_18->text().toInt();     ui.label_24->setText("Welcome ! "+ manager_name+".");     ui.lineEdit_17->setText("");     ui.lineEdit_18->setText("");       {         ui.tabWidget->addTab(ui.tab_2,QString::fromLocal8Bit("单本插入/删除"));         ui.tabWidget->addTab(ui.tab_3,QString::fromLocal8Bit("批量入库"));         ui.tabWidget->addTab(ui.tab_4,QString::fromLocal8Bit("借阅管理"));         ui.tabWidget->addTab(ui.tab_5,QString::fromLocal8Bit("用户信息管理"));         ui.tabWidget->addTab(ui.tab_6,QString::fromLocal8Bit("创建用户"));         ui.tabWidget->addTab(ui.tab_7,QString::fromLocal8Bit("借书记录"));         ui.tabWidget->addTab(ui.tab_8,QString::fromLocal8Bit("管理员信息"));           connect(ui.tabWidget, SIGNAL(currentChanged(int)),this,SLOT(empty(int)));       }     { //set the buttom         bool ok =false;         ui.label_25->setVisible(ok);         ui.label_26->setVisible(ok);         ui.lineEdit_17->setVisible(ok);         ui.lineEdit_18->setVisible(ok);         ui.pushButton_12->setVisible(ok);         ui.label_24->setVisible(!ok);         ui.pushButton->setVisible(!ok);     } }

界面：

 

 

 

2.图书入库

核心代码

/*单本插入*/ voidBookSystem::SL_insert1() {     if(SL_insert_book(ui.lineEdit_8->text(), ui.lineEdit_4->text(), ui.lineEdit_5->text(), ui.lineEdit_6->text(),         ui.lineEdit_7->text(), ui.lineEdit_9->text(), ui.lineEdit_10->text()))     {         select_model_insert1->select();//更新显示         QMessageBox::about(0,QObject::tr("SUCCESS"),"Success in inserting book <"+ ui.lineEdit_4->text()+">");         SL_insert1_empty();       }   }   boolBookSystem::SL_insert_book(QStringType,QStringTitle,QStringPublisher,     QStringPublish_year,QString Author,QStringPrice,QStringNumber) {     QString ID;       //如果标题为空     if (""==Title )     {         QMessageBox::warning(0,QObject::tr("INACCURACY DATA"),"Please put in accurate name");         return false;     }         //如果得到的是零或者负数     int number_in =Number.toInt();     if (number_in <= 0)     {         QMessageBox::warning(0,QObject::tr("INACCURACY DATA"),"Please check the number");         return false;     }     QString number =QString::number(number_in, 10);//取整         //根据type生成ID     QSqlQuery query_getID("select MAX(Book_id)+1 from book where Type = '"+Type+"'");       if (query_getID.next())     {         ID = query_getID.value(0).toString();     }     if (ID=="")//如果这个类型还没有书     {         QSqlQuery query_temp("select Type_number * 1000 + 1 from type where Book_type = '"+Type+"'");         ui.plainTextEdit_3->setPlainText(ID);           if (query_temp.next())         {             ID = query_temp.value(0).toString();         }         else         {             QMessageBox::warning(0,QObject::tr("NO SUCH TYPE"),"make sure you add the accuracy type");             returnfalse;         }     }           //插入     QSqlQuery insert;     insert.prepare("INSERT INTO book (Book_id,Type,Title,Publisher,Publish_year,Author,Price,Number,Stocks) "         "VALUES (?,?,?,?,?,?,?,?,?);");     insert.addBindValue(ID);     insert.addBindValue(Type);     insert.addBindValue(Title);     insert.addBindValue(Publisher);     insert.addBindValue(Publish_year);     insert.addBindValue(Author);     insert.addBindValue(Price);     insert.addBindValue(Number);     insert.addBindValue(Number);     insert.exec();       if (!insert.isActive())     {         QMessageBox::warning(0,QObject::tr("Database Error"),"Please check the input ,especially the accurcy in publish year,"             "or maybe the ID need to be reset.");         //数据库返回错误的几种可能性 1.主键约束即 ID的生成有一定不合理性 2.trigger的约束 年份大于1800 小于现在的年份         returnfalse;     }       returntrue; }

 

界面：

单本插入：

删除：

批量入库（QSqlRecord介绍时附过相关代码）

3.图书查询

模糊查询 使用”$”匹配

4.借书

查询信息

无库存

超过借书限制

5.还书

1.      借书证管理

 

 

2.      显示

 

3.      撤销操作

if (!db.rollback()) {         QMessageBox::warning(0,QObject::tr("Database Error"), db.lastError().text());     }     else     {         QMessageBox::about(0,QObject::tr("Database Error"),"Success in Rollback");     }

 

 

附录

代码下载

https://github.com/birdy-C/BookSystem.git