database.cpp

C++实现简单数据库管理系统

#include "file.h"
void show_welcome()
{
	cout<<"*************************************************\n";
	cout<<"*                 Tiny In-Men DataBase\n";
	cout<<"*             Copyright reserved.\n";
	cout<<"*************************************************\n";
}
void show_bye()
{
	cout<<"bye\n";
	system("pause");
	exit(0);
}
void show_help()
{	
	cout<<"help:\n";
	//cout<<"DB=>";
}
int main()
{
	show_welcome();
	SQL.clear();
	while(1)
	{
		cout<<"DB=>";
		string cmd;
		getline(cin,cmd,'\n');
		istringstream explain(cmd);
		string temp_cmd;
		explain>>temp_cmd;
		if(temp_cmd=="-h")
		{
			show_help();
		}
		else if(temp_cmd=="-q")
		{
			show_bye();
			break;
		}
		else if(temp_cmd=="-c")
		{
			explain>>temp_cmd;
			int return_code = create_table(temp_cmd.c_str());
			if(return_code==0)
			{
				cout<<"please check whether the path and the file is right!!!\n";
				//continue;
			}
			else if (return_code==1)
			{
				cout<<"the format of the content in the create file is not right,please check it\n";
				//continue;
			}
			else
			{
				cout<<"Create the table completed\n";
				//continue;
			}
		}
		else if(temp_cmd=="-i")
		{
			string table_name;
			string data_path;
			explain>>table_name>>data_path;	
			int return_code = establish(table_name,data_path.c_str());
			if(-1==return_code)
			{
				cout<<"please check the table name and the file path and try it again!!!\n";
				//continue;
			}
			else if(-2==return_code)
			{
				cout<<"please check the file path and try it again!!!\n";
				//continue;
			}
			else
			{
				cout<<"Import the data completed!!!\n";
				cout<<return_code<<" records imported successfully!!!\n";
				//continue;
			}
		}
		else if(temp_cmd=="-s")
		{
			explain>>temp_cmd;
			select(temp_cmd.c_str());
			
		}
		else if(temp_cmd=="-u")
		{
			explain>>temp_cmd;
			update(temp_cmd.c_str());
			
		}
		else if(temp_cmd=="-d")
		{
			explain>>temp_cmd;
			int return_code = delete_data(temp_cmd.c_str());
			if (return_code==0)
			{
				cerr<<"please check the file name and the file path and try it again!!!\n";
				//continue;
			}
			else if (return_code==1)
			{
				cerr<<"the content in the file is not right,please check it\n";
				//continue;
			}
			else
			{
				cout<<"delete successfully\n";
				//continue;
			}
			
			
		}
		else if(temp_cmd=="-index")
		{
			int index_num = 0;
			explain>>index_num;
			cout<<index_num;
			
		}
		else
		{
			cout<<"wrong input  you may type: -h to get more help\n";
			//continue;
		}
	}
	return 0;
}