dbcxxexception.cpp~

来自「这是我用QT和TTS写的一个电话本管理系统」· CPP~ 代码 · 共 78 行

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//only this head should include for use bdb.
#include "db_cxx.h"
#include "db.h"
int main()
{ 
	//Creat and Open my_db.db 
	Db db(NULL, 0); // Instantiate the Db object
	u_int32_t oFlags = DB_CREATE; // Open flags;
	try 
	{
		// Open the database
		db.open(NULL, // Transaction pointer
				"my_db.db", // Database file name
				NULL, // Optional logical database name
				DB_BTREE, // Database access method
				oFlags, // Open flags
				0); // File mode (using defaults)
	}
	// DbException is not subclassed from std::exception, so
	// need to catch both of these. 
	catch(DbException &e) 
	{
		// Error handling code goes here
		std::cerr << e.what() << std::endl;
	} 
	catch(std::exception &e) 
	{
		// Error handling code goes here
		std::cerr << e.what() << std::endl;
	}

	//Put Data into my_db.db
	char *description = "Grocery bill.";
	float money = 122;
	Dbt pkey(&money, sizeof(float));
	Dbt pdata(description, strlen(description) + 1);
	int ret = db.put(NULL, &pkey, &pdata, DB_NOOVERWRITE);
	if (ret == DB_KEYEXIST)
	{
		db.err(ret, "Put failed because key %f already exists", money);
	}
	else
	{
		printf("db: %s: data stored.\n", pdata.get_data());}
		//Get Data from my_db.db
		// Use our own memory to retrieve the float.
		// For data alignment purposes.
		//pkey.set_data(&money);
		//pkey.set_ulen(sizeof(float));
		//pkey.set_flags(DB_DBT_USERMEM);
		db.get(NULL, &pkey, &pdata, 0);
		printf("db: %s=%f: data get.\n", (char *)pdata.get_data(),money);
		//Delet Data from my_db.db
		db.del(NULL, &pkey, 0);
		//Close my_db.db
		try
		{
			// Close the database
			db.close(0);
		}
		// DbException is not subclassed from std::exception, so
		// need to catch both of these.
 		catch(DbException &e)
 		{
 			// Error handling code goes here
			std::cerr << e.what() << std::endl;
		}	 
		catch(std::exception &e) {
		// Error handling code goes here
		std::cerr << e.what() << std::endl;
	}
	return(0);
}