酒店点餐系统开发详解四

酒店点餐系统开发详解（四）

——数据库模块设计

在本系统中每个模块与数据库的一系列查询、插入、删除等操作是通过类CDatabaSEOperation进行的，所有的数据库操作都封装在这个类中。数据库功能的封装增加了模块的独立性和复用性，便于进行二次开发和软件的修改。

本系统采用ADO对象进行数据库操作，故应在stdafx.h中添加“#import "c:/program files/common files/system/ado/msado15.dll" no_namespace rename("EOF","_EOF")”（不包括引号），每个模块刚启动并连接数据库的操作如下：

BOOL CCookTerminalApp::InitInstance()

{

……

AfxEnableControlContainer();

::CoInitialize(NULL);//初始化com环境

//网络连接初始化

AfxSocketinit(NULL);

//数据库连接

ConnectsqlServer();

……

}

//连接数据库

void CCookTerminalApp::ConnectsqlServer()

{

CString IP,User,Passwd;

int Port;

GetPrivateProfileString("sqlServer","IP","local",IP.GetBuffer(20),20,".//default.ini");

IP.ReleaseBuffer();

GetPrivateProfileString("sqlServer","User","sa",User.GetBuffer(20),".//default.ini");

User.ReleaseBuffer();

GetPrivateProfileString("sqlServer","Passwd","",Passwd.GetBuffer(20),".//default.ini");

Passwd.ReleaseBuffer();

Port = GetPrivateProfileInt("sqlServer","Port",1433,".//default.ini");

//数据库连接初始化

m_DbOp.CreateInstance();

if(IP == "local")

m_DbOp.OpenLocalDatabase("dishesSystem");

else{

CString str;

str.Format("%s,%d",IP,Port);

m_DbOp.OpenRemoteDatabase(str,"dishesSystem",Passwd);

}

类CDatabaSEOperation的具体接口及实现如下：

1、创建实例

void CDatabaSEOperation::CreateInstance()

{

cnn.CreateInstance(__uuidof(Connection));

rst.CreateInstance(__uuidof(Recordset));

}

2、打开本地数据库

void CDatabaSEOperation::OpenLocalDatabase(CString basename)

{

CString str;

str.Format(_T("Provider=sqlOLEDB.1;Data Source=(local);Initial Catalog=%s;Integrated Security=sspI"),basename);

cnn->ConnectionString = (_bstr_t)str;

try{

cnn->Open(L"",L"",adCmdUnspecified);

}catch(_com_error &e){

CatchError(e);

}

3、打开远程数据库

void CDatabaSEOperation::OpenRemoteDatabase(CString source, CString basename, CString user, CString pwd)

{

CString str;

str.Format(_T("Provider=sqlOLEDB.1;Data Source=%s;Network Library=DBMSSOCN;Initial Catalog=%s;User ID=%s;Password=%s"),source,basename,user,pwd);

cnn->ConnectionString = (_bstr_t)str;

try{

cnn->Open(L"",adCmdUnspecified);

}catch(_com_error &e){

CatchError(e);

}

4、打开记录集

BOOL CDatabaSEOperation::OpenRecordset(CString sqlstatement)

{

CloseRecordset();

try{

rst->CursorLocation = adUseClient;

rst->Open((_variant_t)sqlstatement,_variant_t((Idispatch *)cnn,true),adOpenDynamic,adLockpessimistic,adCmdText);

}catch(_com_error &e){

// CatchError(e);

return FALSE;

}

return TRUE;

}

5、关闭记录集

void CDatabaSEOperation::CloseRecordset()

{

if(rst->State)

rst->Close();

}

6、返回记录集

_RecordsetPtr CDatabaSEOperation::GetRecordset(CString sqlstatement)

{

_RecordsetPtr rst;

rst.CreateInstance(__uuidof(Recordset));

try{

rst->CursorLocation = adUseClient;

rst->Open((_variant_t)sqlstatement,adCmdText);

}catch(_com_error &e){

// CatchError(e);

return NULL;

}

return rst;

}

7、插入新数据

BOOL CDatabaSEOperation::InsertItem(CString sqlstatement)

{

try{

cnn->Execute((_bstr_t)sqlstatement,NULL,adCmdText);

}catch(_com_error &e){

CatchError(e);

return FALSE;

}

return TRUE;

}

8、修改数据

BOOL CDatabaSEOperation::UpdateItem(CString sqlstatement)

{

try{

cnn->Execute((_bstr_t)sqlstatement,adCmdText);

}catch(_com_error &e){

CatchError(e);

return FALSE;

}

return TRUE;

}

9、删除数据

BOOL CDatabaSEOperation::DeleteItem(CString sqlstatement)

{

try{

cnn->Execute((_bstr_t)sqlstatement,adCmdText);

}catch(_com_error &e){

CatchError(e);

return FALSE;

}

return TRUE;

}

10、返回属性值

CString CDatabaSEOperation::GetAttrValues(CString attr)

{

_variant_t vt;

CString values;

if(rst->_EOF || rst->BOF)

return "";

try{

vt = rst->GetCollect((_variant_t)attr);

}catch(_com_error &e){

CatchError(e);

return "";

}

values = (LPCSTR)_bstr_t(vt);

return values;

}

11、读取数据库图片数据

char *CDatabaSEOperation::ReadPictureData(CString sqlstatement, CString attrName)

{

_RecordsetPtr temp_rst;

char *buf = NULL;

temp_rst.CreateInstance(__uuidof(Recordset));

try{

temp_rst->Open((_variant_t)sqlstatement,adCmdText);

}catch(_com_error &e){

CatchError(e);

return NULL;

}

long lDataSize;

try{

lDataSize = temp_rst->GetFields()->GetItem((_variant_t)attrName)->ActualSize;

}catch(_com_error &e){

CatchError(e);

return NULL;

}

if(lDataSize > 0)

{

_variant_t varBLOB;

try{

varBLOB = temp_rst->GetFields()->GetItem((_variant_t)attrName)->GetChunk(lDataSize);

}catch(_com_error &e){

CatchError(e);

return NULL;

}

if(varBLOB.vt == (VT_ARRAY | VT_UI1))

{

if(buf = new char[lDataSize+1]) ///重新分配必要的存储空间

{

char *pBuf = NULL;

SafeArrayAccessData(varBLOB.parray,(void **)&pBuf);

memcpy(buf,pBuf,lDataSize); ///复制数据到缓冲区

SafeArrayUnaccessData (varBLOB.parray);

}

return buf;

}

12、保存图片到数据库

BOOL CDatabaSEOperation::SavePicture(CString sqlstatement, CString attrName, char *buf, long len)

{

if(buf == NULL)

return TRUE;

char *pBuf = buf;

VARIANT varBLOB;

SAFEARRAY *psa;

SAFEARRAYBOUND rgsabound[1];

_RecordsetPtr temp_rst;

temp_rst.CreateInstance(__uuidof(Recordset));

try{

temp_rst->Open((_variant_t)sqlstatement,adCmdText);

}catch(_com_error &e){

CatchError(e);

return FALSE;

}

if(temp_rst->_EOF)

return FALSE;

if(pBuf)

{

rgsabound[0].lLbound = 0;

rgsabound[0].cElements = len;

psa = SafeArrayCreate(VT_UI1, 1, rgsabound);

for (long i = 0; i < (long)len; i++)

SafeArrayPutElement (psa, &i, pBuf++);

varBLOB.vt = VT_ARRAY | VT_UI1;

varBLOB.parray = psa;

temp_rst->GetFields()->GetItem((_variant_t)attrName)->AppendChunk(varBLOB);

}

temp_rst->Update();

temp_rst->Close();

return TRUE;

}

在实际的操作中，我们将常用的数据库操作整理为存储过程编译到数据库中，以下就是本系统所涉及的具体存储过程：

从厨师表中删除厨师（DeleteCook @cookid ）

1）本过程先查看点菜表中是否存在相关记录，若存在，则不允许删除厨师，因为顾客还没结账；若不存在，则先删除做菜表中记录，再删除厨师表中记录。

--删除厨师，需先将CookingTable和dishedTable中的相关项删除

CREATE PROCEDURE DeleteCook @cookid char(8)

--如果点菜表中含有相关项，说明顾客未结账，则不允许删除

IF EXISTS (SELECT * FROM dishedTable WHERE cookid=@cookid)

RETURN

ELSE

IF EXISTS (SELECT * FROM CookingTable WHERE cookid=@cookid)

DELETE FROM CookingTable WHERE cookid=@cookid

DELETE FROM CookTable WHERE cookid=@cookid

2）从菜品表中删除菜品（Deletedish @dishid）

本过程同样先检查点菜表中是否有相关项，若有，则不允许删除菜品；若无，则先删除做菜表中记录，再删除菜品表中记录。

--删除菜品信息，先检查dishedTable和CookingTable中有无相关项

CREATE PROCEDURE Deletedish @dishid char(8)

--如果点菜表中含有相关项，说明顾客未结账，则不允许删除

IF EXISTS (SELECT * FROM dishedTable WHERE dishid=@dishid)

RETURN

ELSE

IF EXISTS (SELECT * FROM CookingTable WHERE dishid=@dishid)

DELETE FROM CookingTable WHERE dishid=@dishid

DELETE FROM dishesTable WHERE dishid=@dishid

3）销售统计（Salesstatistics @date,@sales）

本过程首先检查表中是否存在日期相同的记录，若存在，则将原记录中的销售额加上新数据；若不存在，则直接插入新数据。

--销售统计函数

CREATE PROCEDURE Salesstatistics @date char(10),@sales float

--如果表中存在该项，则增加销售额

IF EXISTS (SELECT * FROM SalesstatisticsTable WHERE date=@date)

UPDATE SalesstatisticsTable SET sales=sales+@sales WHERE date=@date

ELSE

--否则，插入新数据

INSERT INTO SalesstatisticsTable (date,sales) VALUES(@date,@sales)

4）搜索拿手菜表（SearchSpecialty @cookname）

若cookname为'%%'，则显示所有表中数据，否则，显示某一厨师的拿手菜信息。所返回结果先按厨师名排序，然后再按喜爱度排序。

--搜索拿手菜表

CREATE PROCEDURE SearchSpecialty @cookname nchar(50)

IF @cookname='%%'

SELECT DT.dishid as 菜品编号,LEFT(dishname,LEN(dishname)) as 菜品名称,

CT.cookid as 厨师编号,LEFT(cookname,LEN(cookname)) as 厨师姓名,

average as 喜爱度,dishprice as 菜品单价

FROM SpecialtyTable ST INNER JOIN dishesTable DT ON ST.dishid=DT.dishid

INNER JOIN CookTable CT ON ST.cookid=CT.cookid

ORDER BY cookname ASC,average DESC --先按厨师名排序，再按平均分排序

ELSE

SELECT DT.dishid as 菜品编号,dishprice as 菜品单价

FROM SpecialtyTable ST INNER JOIN dishesTable DT ON ST.dishid=DT.dishid

INNER JOIN CookTable CT ON ST.cookid=CT.cookid

WHERE cookname LIKE @cookname

ORDER BY cookname ASC,average DESC --先按厨师名排序，再按平均分排序

5）点菜（dishedFuction @dishedtime ,@deskid @dishid ,@cookid）

本过程先查看表中是否存在相同记录，若存在，则将所点菜品份数amount加1，菜品总价cost自动加上相应菜品单价；若不存在，则直接插入新数据。

--点菜操作

CREATE PROCEDURE dishedFuction

@dishedtime char(19),@deskid int,@dishid char(8),@cookid char(8)

DECLARE @price float

SELECT @price=dishprice FROM dishesTable WHERE dishid=@dishid

IF EXISTS (SELECT * FROM dishedTable WHERE dishedtime=@dishedtime AND deskid=@deskid AND dishid=@dishid)

UPDATE dishedTable SET amount=amount+1,cost=cost+@price

WHERE dishedtime=@dishedtime AND deskid=@deskid AND dishid=@dishid

ELSE

INSERT INTO dishedTable (dishedtime,deskid,dishid,cookid,cost,amount)

VALUES(@dishedtime,@deskid,@dishid,@cookid,@price,1)

6）退菜（ReturndishFuction @dishedtime,@dishid）

本过程先查看菜品份数amount是否为1，若为1，则直接删除该记录；若不为1，则将菜品份数amount减1，然后菜品总价cost减去相应菜品单价。

--退菜操作

CREATE PROCEDURE ReturndishFuction

@dishedtime char(19),@dishid char(8)

AS DECLARE @price float

SELECT @price=dishprice FROM dishesTable WHERE dishid=@dishid

--如果点菜表中存在该项则将点菜份数-1，菜品总价递减

IF EXISTS (SELECT * FROM dishedTable WHERE dishedtime=@dishedtime AND deskid=@deskid AND dishid=@dishid)

BEGIN DECLARE @amount int

SELECT @amount=amount FROM dishedTable WHERE dishedtime=@dishedtime AND deskid=@deskid AND dishid=@dishid

IF @amount=1

DELETE FROM dishedTable WHERE dishedtime=@dishedtime AND deskid=@deskid AND dishid=@dishid

ELSE

UPDATE dishedTable SET amount=amount-1,cost=cost-@price

WHERE dishedtime=@dishedtime AND deskid=@deskid AND dishid=@dishid

END

7）评分（scoreFuction @cookid,@dishid ,@score）

本过程先检查表中是否存在相同记录，若存在，则将评分次数freq加1，总分scores加上此次分数，并计算平均分；若不存在，则插入新数据。

--对厨师所做菜品进行评分

CREATE PROCEDURE scoreFuction @cookid char(8),@score int

--如果表中存在该项，则将评次加1，总分增加，并求出平均分

IF EXISTS (SELECT * FROM CookingTable WHERE cookid=@cookid AND dishid=@dishid)

BEGIN

DECLARE @f int,@s int,@a int

SELECT @f=freq,@s=scores FROM CookingTable WHERE cookid=@cookid AND dishid=@dishid

SET @f=@f+1

SET @s=@s+@score

SET @a=@s/@f

UPDATE CookingTable SET freq=@f,scores=@s,average=@a

WHERE cookid=@cookid AND dishid=@dishid

END

ELSE

INSERT INTO CookingTable (cookid,freq,scores,average)

VALUES(@cookid,1,@score,@score)

8）搜索点菜表（Searchdished @dishedtime ,@deskid）

本过程用于向顾客返回其所点菜品信息，并对厨师所做菜品进行评分。

--搜索点菜表

CREATE PROCEDURE Searchdished @dishedtime char(19),@deskid int

SELECT DdT.dishid as 菜品编号,

DdT.cookid as 厨师编号,

amount as 点菜份数,cost as 菜品总价

FROM dishedTable DdT INNER JOIN dishesTable DsT ON DdT.dishid=DsT.dishid

INNER JOIN CookTable CkT ON DdT.cookid=CkT.cookid

WHERE dishedtime=@dishedtime AND deskid=@deskid

9）获取账单信息（GetAccountInfo @dishedtime,@deskid）

本过程用于结账时显示顾客所点菜品的详细信息。

--获取账单详细信息

CREATE PROCEDURE GetAccountInfo @dishedtime char(19),cost as 总价

FROM dishedTable DdT INNER JOIN dishesTable DsT ON DdT.dishid=DsT.dishid

INNER JOIN CookTable CkT ON DdT.cookid=CkT.cookid

WHERE dishedtime=@dishedtime AND deskid=@deskid

10）搜索菜品表（Searchdishes @dishname）

本过程显示搜索菜品表的结果。

--搜索菜品表

CREATE PROCEDURE Searchdishes @dishname nchar(50)

IF @dishname='%%%%'

SELECT dishid as 菜品编号,dishprice as 菜品单价

FROM dishesTable

ELSE

SELECT dishid as 菜品编号,dishprice as 菜品单价

FROM dishesTable WHERE dishname LIKE @dishname

源代码下载地址：http://download.csdn.net/source/2406335 标题有误，请见谅...

酒店点餐系统开发详解四

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