C++数据库操作

新手C++对于数据库操作

首先需要新建一个access文件。

//主函数
#include<iostream>
#include<map>
#include <string>
#include "inquire.h"
using namespace std;
void main()
{
	CoInitialize(NULL);	//初始化环境
	inquire Inquire("xxx.mdb");//填自己存放的access文件地址，记得不能写错。
	if ((Inquire.getmyerror().length() )!= 0)
	{
		cout << "数据库连接失败";
		cout << Inquire.getmyerror();
		getchar();

	}

	//下面是三种操作对数据库进行添加删除和转化为数组形式查询
	//① 添加操作
/*	map<int, string> add;	
		cin >> add[0];
		cin >> add[1];
		cin >> add[2];
		Inquire.insertion("表1",add);
		if (Inquire.getmyerror().length() == 0)
		{
			cout << "插入成功\n";
			getchar();
		}
		else
		{
			cout <<Inquire.getmyerror();
			getchar();
		}
*/

	//② 删除操作
/*		
		map<int, string> delet;
		cin >> delet[0];//表名
		cin >> delet[1];//删除条件
		if(!Inquire.Delete(delet[0],delet[1]))
		{
		cout<<"删除失败";
		cout<<Inquire.getmyerror();
		getchar();
		}	

	*/	
	
	//③查询表格	
		
/*	map<int ,map<int,string>>check;
	Inquire.check_table(check);		
	 if (Inquire.getmyerror().length() == 0)
	 {

		 for (int i = 0; i < check.size(); i++)
		 {
			 map<int, string> aaa = check[i];
			 for (size_t u = 0; u < aaa.size(); u++)
			 {
				 string str = aaa[u];
				 cout << str.c_str()<<"\t";

			 }
			 cout << "\n";
		 }
		 getchar();

	 }
	 else
	 {
		 cout << Inquire.getmyerror();
		 getchar();
	 }
	 */
	 	CoUninitialize();
	
	return  ;
}

//类的头文件
#pragma once
#include<map>
#include<iostream>
#include<string>
#import "c:\program files\common files\system\ado\msado15.dll"  no_namespace  rename ("EOF", "adoEOF")
using namespace std;
class inquire
{
public:
	inquire(string phat);
	~inquire();
	string getmyerror();
	void insertion(string, map<int, string>);
	bool Delete(string,string);
	void check_table(map<int, map<int, string>> &mp);
private:
	_ConnectionPtr m_pConnection;
	_RecordsetPtr m_pRecordset;
	HRESULT hr;
	string m_error;

};


//函数的类

#include "inquire.h"

inquire::inquire(string phat)

{
	m_error = "";
	try {
		hr = m_pConnection.CreateInstance("ADODB.Connection");//ADO方式连接

		if (SUCCEEDED(hr))
		{
			m_pConnection->ConnectionTimeout = 5;
			string 路径;
			路径 = " Provider = Microsoft.Jet.OLEDB.4.0; Data Source =" + phat;
			hr = m_pConnection->Open(路径.c_str(), "", "", adModeUnknown);
		}
	}
	catch (_com_error e)///捕捉异常
	{
		string m_error= e.ErrorMessage()；		
	}

}

inquire::~inquire()
{
	if (m_pConnection->State)
	{
		m_pConnection->Close();
		m_pConnection = NULL;
	}
}


string inquire::getmyerror()
{
	return m_error;
}


void inquire::insertion(string table_name,map<int,string> train_value)
{
	m_error = "";
	try {
		_variant_t RecordsAffected;
		string sql;
		sql = "INSERT INTO " + table_name + "( name,old,height)VALUES(";
		for (size_t i = 0; i < train_value.size(); i++)
		{
			sql += train_value[i] + ",";
		}
		sql = sql.substr(0, sql.length() - 1) + ")";

		m_pConnection->Execute(sql.c_str(), &RecordsAffected, adCmdText);
		
	}

	catch (_com_error e)///捕捉异常
	{
		 m_error = e.ErrorMessage();
	}
}

bool inquire::Delete(string table_name, string condition)//删除
{
	m_error = "";
	try
	{
	
		_variant_t RecordsAffected;
		string shanchu;
		shanchu = "DELETE FROM " + table_name + " WHERE " + condition;
		m_pConnection->Execute(shanchu.c_str(), &RecordsAffected, adCmdText);
		return true;
	}
	catch (_com_error e)///捕捉异常
	{
		m_error = e.ErrorMessage();
		return false;
	}
}

void inquire::check_table(map<int, map<int, string>> &mp)
{
	try
	{
		m_error = "";
		m_pRecordset.CreateInstance(_uuidof(Recordset));
		char sql[300];
		memset(sql, 0, 300);
		strcat(sql, "SELECT * FROM 表1");
		m_pRecordset->Open(sql, (IDispatch*)m_pConnection, adOpenDynamic, adLockOptimistic, adCmdText);

	}
	catch (_com_error e)///捕捉异常
	{
		m_error = e.ErrorMessage();
	}
	try
	{

		if (m_pRecordset->BOF)
		{
			printf("表内数据为空");
			if (m_pConnection->State)
			{
				m_pRecordset->Close();
				m_pRecordset = NULL;
				m_pConnection->Close();
				m_pConnection = NULL;
			}
			CoUninitialize();
			return;

		}
		cout << "this is my database \n";
		m_pRecordset->MoveFirst();
		int i,u=0 ;
		while (!m_pRecordset->adoEOF)
		{
			int row = m_pRecordset->GetFields()->Count;
			_variant_t var[100];
			for (i = 0; i < row; i++)
			{
				var[i] = m_pRecordset->GetCollect(_variant_t((long)i));
				if (var[i].vt != VT_NULL)
				{
					mp[u][i] = _com_util::ConvertBSTRToString((_bstr_t)var[i]);
				}
				else
				{
					mp[u][i] = "";
				}
			}
				m_pRecordset->MoveNext();
				u++;
		}

	}

			catch (_com_error e)///捕捉异常
			{
				m_error = e.ErrorMessage();
			}

		}
	
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这是简单数据库操作，望采纳！