databasesample.c

有关数据库操作的例子

/*===========================================================================

FILE: databasesample.c
===========================================================================*/


/*===============================================================================
INCLUDES AND VARIABLE DEFINITIONS
=============================================================================== */
#include "AEEModGen.h"          // Module interface definitions
#include "AEEAppGen.h"          // Applet interface definitions
#include "AEEShell.h"           // Shell interface definitions
#include "AEEFile.h"			// File interface definitions
#include "AEEDB.h"				// Database interface definitions

#include "databasesample.bid"

/*-------------------------------------------------------------------
Function Prototypes
-------------------------------------------------------------------*/
static boolean databasesample_HandleEvent(IApplet * pi, AEEEvent eCode, 
                                      uint16 wParam, uint32 dwParam);

/*===============================================================================
FUNCTION DEFINITIONS
=============================================================================== */
static boolean AddRecordToDB(IShell *pIShell);
static boolean DelRecordFromDB(IShell *pIShell);

/*===========================================================================

FUNCTION: AEEClsCreateInstance

DESCRIPTION
	This function is invoked while the app is being loaded. All Modules must provide this 
	function. Ensure to retain the same name and parameters for this function.
	In here, the module must verify the ClassID and then invoke the AEEApplet_New() function
	that has been provided in AEEAppGen.c. 

   After invoking AEEApplet_New(), this function can do app specific initialization. In this
   example, a generic structure is provided so that app developers need not change app specific
   initialization section every time except for a call to IDisplay_InitAppData(). 
   This is done as follows: InitAppData() is called to initialize AppletData 
   instance. It is app developers responsibility to fill-in app data initialization 
   code of InitAppData(). App developer is also responsible to release memory 
   allocated for data contained in AppletData -- this can be done in 
   IDisplay_FreeAppData().

PROTOTYPE:
   int AEEClsCreateInstance(AEECLSID ClsId,IShell * pIShell,IModule * po,void ** ppObj)

PARAMETERS:
	clsID: [in]: Specifies the ClassID of the applet which is being loaded

	pIShell: [in]: Contains pointer to the IShell object. 

	pIModule: pin]: Contains pointer to the IModule object to the current module to which
	this app belongs

	ppObj: [out]: On return, *ppObj must point to a valid IApplet structure. Allocation
	of memory for this structure and initializing the base data members is done by AEEApplet_New().

DEPENDENCIES
  none

RETURN VALUE
  AEE_SUCCESS: If the app needs to be loaded and if AEEApplet_New() invocation was
     successful
  EFAILED: If the app does not need to be loaded or if errors occurred in 
     AEEApplet_New(). If this function returns FALSE, the app will not be loaded.

SIDE EFFECTS
  none
===========================================================================*/
int AEEClsCreateInstance(AEECLSID ClsId,IShell * pIShell,IModule * po,void ** ppObj)
{
   *ppObj = NULL;
		
   if(ClsId == AEECLSID_DATABASESAMPLE){
      if(AEEApplet_New(sizeof(AEEApplet), ClsId, pIShell,po,(IApplet**)ppObj,
         (AEEHANDLER)databasesample_HandleEvent,NULL)
         == TRUE)
      {
		 // Add your code here .....

         return (AEE_SUCCESS);
      }
   }
	return (EFAILED);
}

/*===========================================================================

FUNCTION databasesample_HandleEvent

DESCRIPTION
	This is the EventHandler for this app. All events to this app are handled in this
	function. All APPs must supply an Event Handler.

PROTOTYPE:
	boolean databasesample_HandleEvent(IApplet * pi, AEEEvent eCode, uint16 wParam, uint32 dwParam)

PARAMETERS:
	pi: Pointer to the AEEApplet structure. This structure contains information specific
	to this applet. It was initialized during the AEEClsCreateInstance() function.

	ecode: Specifies the Event sent to this applet

   wParam, dwParam: Event specific data.

DEPENDENCIES
  none

RETURN VALUE
  TRUE: If the app has processed the event
  FALSE: If the app did not process the event

SIDE EFFECTS
  none
===========================================================================*/
static boolean databasesample_HandleEvent(IApplet * pi, AEEEvent eCode, uint16 wParam, uint32 dwParam)
{  
	AECHAR hints1[6] = {'(','N', 'O', 'T', 'E', ')'};
	AECHAR hints2[12] = {'P','r','e','s','s',' ','1',' ','A','D','D','!'};
	AECHAR hints3[12] = {'P','r','e','s','s',' ','2',' ','D','E','L','!'};

	AECHAR hints4[12] = {'A','D','D',' ','S','u','c','c','e','s','s','!'};
	AECHAR hints5[11] = {'A','D','D',' ','F','a','i','l','e','d','!'};
	
	AECHAR hints6[12] = {'D','E','L',' ','S','u','c','c','e','s','s','!'};
	AECHAR hints7[11] = {'D','E','L',' ','F','a','i','l','e','d','!'};

	AEEApplet *pAEEApplet = (AEEApplet *)pi;
	IDisplay  *pIDisplay  = pAEEApplet->m_pIDisplay;
	IShell	  *pIShell    = pAEEApplet->m_pIShell;

   switch (eCode) 
	{
      case EVT_APP_START:                        
		    IDISPLAY_ClearScreen(pIDisplay);
			IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints1,
				6, 0, 20, NULL, IDF_ALIGN_CENTER);
			IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints2, 
				12, 0, 40, NULL, IDF_ALIGN_CENTER);
			IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints3,
				12, 0, 60, NULL, IDF_ALIGN_CENTER);
			IDISPLAY_Update(pIDisplay);
		    // Add your code here .....

      		return(TRUE);
      case EVT_APP_STOP:
	
		    // Add your code here .....
	  case EVT_KEY:
		  switch(wParam)
		  {
		  case AVK_1:
			  IDISPLAY_ClearScreen(pIDisplay);
			  IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints1,
				6, 0, 20, NULL, IDF_ALIGN_CENTER);
			  IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints2, 
				12, 0, 40, NULL, IDF_ALIGN_CENTER);
			  IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints3,
				12, 0, 60, NULL, IDF_ALIGN_CENTER);
			  if(AddRecordToDB(pIShell) == SUCCESS){
				IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints4,
					12, 0, 90, NULL, IDF_ALIGN_CENTER);
			  }
			  else{
				IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints5,
					11, 0, 90, NULL, IDF_ALIGN_CENTER);
			  }
			  IDISPLAY_Update(pIDisplay);
			  
			  return TRUE;
		  case AVK_2:
			  IDISPLAY_ClearScreen(pIDisplay);
			  IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints1,
				6, 0, 20, NULL, IDF_ALIGN_CENTER);
			  IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints2, 
				12, 0, 40, NULL, IDF_ALIGN_CENTER);
			  IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints3,
				12, 0, 60, NULL, IDF_ALIGN_CENTER);
			  if(DelRecordFromDB(pIShell) == SUCCESS){
				IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints6,
					12, 0, 90, NULL, IDF_ALIGN_CENTER);
			  }
			  else{
				IDISPLAY_DrawText(pIDisplay, AEE_FONT_NORMAL, hints7,
					11, 0, 90, NULL, IDF_ALIGN_CENTER);
			  }
			  IDISPLAY_Update(pIDisplay);
			  return TRUE;
		  default:
			  break;
		  }
         return FALSE;
      default:
         break;
   }
   return FALSE;
}


/************************************************************************
/* 函数功能：向数据库中添加一条记录
/*
/* 参数：
/*		pIShell － IShell接口指针
/*
/* 返回值：
/*		SUCCESS － 执行成功
/*		EFAILED -  执行失败                                                                 
************************************************************************/
boolean AddRecordToDB(IShell *pIShell)
{
	//数据库名
	const char *dbName = "zhaowenming";
	//添加的数据
	const char *data = "BREW2.0";
	
	//IDBMgr接口指针
	IDBMgr    *pIDBMgr = NULL;
	//IDatabase接口指针
	IDatabase *pIDatabase = NULL;
	//IDBRecord接口指针
	IDBRecord *pIDBRecord = NULL;

	//记录字段
	AEEDBField dbField;
	dbField.fType = AEEDB_FT_STRING;		//字段类型
	dbField.fName = AEEDBFIELD_FULLNAME;	//字段名称
	dbField.wDataLen = sizeof(data);		//字段的数据长度
	dbField.pBuffer = (void*)data;			//字段数据指针
	
	//创建IDBMgr接口实例
	if(ISHELL_CreateInstance(pIShell, AEECLSID_DBMGR, (void **)&pIDBMgr) != SUCCESS){
		//创建失败
		return EFAILED;
	}
	
	//打开数据库
	if((pIDatabase = IDBMGR_OpenDatabase(pIDBMgr, dbName, TRUE)) == NULL){
		//打开失败
		IDBMGR_Release(pIDBMgr);
		return EFAILED;
	}

	//在数据库中创建一条预先定义的记录记录
	if((pIDBRecord = IDATABASE_CreateRecord(pIDatabase, &dbField, 1)) == NULL){
		//创建失败
		IDATABASE_Release(pIDatabase);
		IDBMGR_Release(pIDBMgr);
		return EFAILED;
	}
	
	//释放IDBRecord接口实例
	IDBRECORD_Release(pIDBRecord);
	//释放IDatabase接口实例
	IDATABASE_Release(pIDatabase);
	//释放IDBMgr接口实例
	IDBMGR_Release(pIDBMgr);
	
	return SUCCESS;
}

/************************************************************************
/* 函数功能：删除数据库中的一条记录
/*
/* 参数：
/*		pIShell － IShell接口指针
/*
/* 返回值：
/*		SUCCESS － 执行成功
/*		EFAILED -  执行失败                                                                 
************************************************************************/
boolean DelRecordFromDB(IShell *pIShell)
{
	//数据库名
	const char *dbName = "zhaowenming";

	//IDBMgr接口指针
	IDBMgr    *pIDBMgr = NULL;
	//IDababase接口指针
	IDatabase *pIDatabase = NULL;
	//IDBRecord接口指针
	IDBRecord *pIDBRecord = NULL;
	
	//创建IDBMgr接口实例
	if(ISHELL_CreateInstance(pIShell, AEECLSID_DBMGR, (void **)&pIDBMgr) != SUCCESS){
		//创建失败
		return EFAILED;
	}
	
	//打开数据库
	if((pIDatabase = IDBMGR_OpenDatabase(pIDBMgr, dbName, TRUE)) == NULL){
		//打开失败
		IDBMGR_Release(pIDBMgr);
		return EFAILED;
	}
	
	//重置数据库的索引，使数据库的访问从头开始
	IDATABASE_Reset(pIDatabase);
	//获得数据库中的一条记录
	if((pIDBRecord = IDATABASE_GetNextRecord(pIDatabase)) == NULL){
		//获取失败
		IDATABASE_Release(pIDatabase);
		IDBMGR_Release(pIDBMgr);
		return EFAILED;
	}
	
	//删除从数据库中获得的记录
	//（注意：删除成功后不用再调用IDBRECORD_Release()来释放IDBRecord接口实例）
	if(IDBRECORD_Remove(pIDBRecord) != SUCCESS)
	{
		//删除失败
		IDBRECORD_Release(pIDBRecord);
		IDATABASE_Release(pIDatabase);
		IDBMGR_Release(pIDBMgr);
		return EFAILED;
	}
	
	//释放IDatabase接口实例
	IDATABASE_Release(pIDatabase);
	//释放IDBMgr接口实例
	IDBMGR_Release(pIDBMgr);

	return SUCCESS;
}