r_command.cpp

小型数据库源代码较多

#include "min.h"

void sql::r_command ( )
{
	cout << "请输入命令：" << endl;
	cin>>command;

	while (strcmp(command, "quit;")) //退出MiniSQL系统
	{
		try{
			if(!strcmp(command, "create")) 
			{
				cin>>command;
				if(!strcmp(command, "table"))
				{
					//创建表语句
					create_table();
				}
				else if(!strcmp(command, "index"))
				{					
					//创建索引语句
					create_index();
				}
				else throw 1;
			}		
			else if(!strcmp(command, "drop")) 
			{	
				cin>>command;
				if(!strcmp(command, "table"))
				{					
					//删除表语句
					drop_table();
				}
				else if(!strcmp(command, "index"))
				{
					//删除索引语句
					drop_index();
				}
				else throw 1;
				}		
				else if(!strcmp(command,"select")) 
				{
				//选择语句
					select_from();
				}
				else if(!strcmp(command,"insert")) 
				{
			
				//插入记录语句
					insert_into();				
				}
				else if(!strcmp(command, "delete")) 
				{
				
				//删除记录语句
					delete_from();
				}			
				else if( !strcmp(command, "execfile") )
				{
				//执行SQL脚本文件语句
					execfile();
				}
				else throw 1;
			}
		catch ( int i )
		{
			switch(i)
			{
			case 1:	cout << "语法错误" << endl;
					break;
			case 2:	cout << "表不存在" << endl;
					break;
			case 3:	cout << "表已经存在" << endl;
					break;
			case 4:	cout << "索引不存在" << endl;
					break;
			case 5:	cout << "索引已经存在" << endl;
					break;
			case 6: cout << "该表不能打开；" << endl;
					break;
			case 7: cout << "没有设设置主键" << endl;
					break;
			case 8: cout << "主键定义中无效的列名" << endl;
					break;
			case 9: cout << "超过了32个属性；请检查！" << endl;
					break;
			case 10: cout << "该属性已存在。" << endl;
					break;
			case 11: cout << "无效的数据类型" << endl;
					break;
		
			case 13: cout << "无法建立索引文件！"<< endl;
					break;
			}
			char a[50];
			cin.getline( a, 50 );
		}

		

		/////////////////////////////////////////////////////////////////
		//                   清空命令行                                //
		/////////////////////////////////////////////////////////////////
		erasecom();

		/////////////////////////////////////////////////////////////////
		//                重新等待输入命令行                           //  
		/////////////////////////////////////////////////////////////////
		cout << "请输入命令:" << endl;
	    cin >> command;
	}
}