conn.CreateInstance(__uuidof(Connection)); conn->ConnectionString = "Provider=SQLOLEDB.1;Data Source=" + server + ";Initial Catalog=" + database + ";User ID=" + username + ";Password='" + password + ";"; conn->Open("", "", "", adConnectUnspecified); 错误

这段代码有什么错误？

这段代码缺少一个单引号，导致连接字符串中的密码没有正确闭合。正确的代码应该是：

conn.CreateInstance(__uuidof(Connection));
conn->ConnectionString = "Provider=SQLOLEDB.1;Data Source=" + server + ";Initial Catalog=" + database + ";User ID=" + username + ";Password='" + password + "';"; 
conn->Open("", "", "", adConnectUnspecified);

注意，我并不知道你的具体要求，这只是对代码错误的修正建议。

相关问题

c++ ado封装sqlserver实现增删查改

以下是使用 C++ 和 ADO 封装 SQL Server 实现增删查改的示例代码：

#include <iostream>
#include <string>
#include <Windows.h>
#import "C:\Program Files\Common Files\System\ado\msado15.dll" no_namespace rename("EOF", "adoEOF")

using namespace std;

class Database {
private:
    _ConnectionPtr conn;  // ADO 连接对象

public:
    // 构造函数，连接数据库
    Database(string server, string database, string username, string password) {
        try {
            conn.CreateInstance(__uuidof(Connection));
            conn->ConnectionString = "Provider=SQLOLEDB.1;Data Source=" + server + ";Initial Catalog=" + database + ";User ID=" + username + ";Password=" + password + ";";
            conn->Open("", "", "", adConnectUnspecified);
        }
        catch (_com_error e) {
            cerr << "Connect to database failed: " << e.ErrorMessage() << endl;
            exit(1);
        }
    }

    // 析构函数，关闭连接
    ~Database() {
        conn->Close();
    }

    // 执行查询语句，并返回查询结果集
    _RecordsetPtr query(string sql) {
        _RecordsetPtr rs;  // ADO 记录集对象

        try {
            rs.CreateInstance(__uuidof(Recordset));
            rs->Open(sql.c_str(), conn.GetInterfacePtr(), adOpenStatic, adLockOptimistic, adCmdText);
        }
        catch (_com_error e) {
            cerr << "Query failed: " << e.ErrorMessage() << endl;
            exit(1);
        }

        return rs;
    }

    // 执行增、删、改语句，并返回受影响的行数
    int execute(string sql) {
        int rows = 0;  // 受影响的行数

        try {
            _variant_t rowsAffected;
            conn->Execute(sql.c_str(), &rowsAffected, adExecuteNoRecords);
            rows = rowsAffected.intVal;
        }
        catch (_com_error e) {
            cerr << "Execute failed: " << e.ErrorMessage() << endl;
            exit(1);
        }

        return rows;
    }
};

int main() {
    // 连接数据库
    Database db("localhost", "test", "sa", "123456");

    // 查询数据
    _RecordsetPtr rs = db.query("SELECT * FROM users");
    while (!rs->adoEOF) {
        cout << rs->Fields->GetItem("id")->Value.intVal << ", " << (char*)(_bstr_t)rs->Fields->GetItem("name")->Value << ", " << rs->Fields->GetItem("age")->Value.intVal << endl;
        rs->MoveNext();
    }

    // 插入数据
    int rows = db.execute("INSERT INTO users (name, age) VALUES ('Tom', 18)");
    cout << "Inserted " << rows << " rows." << endl;

    // 更新数据
    rows = db.execute("UPDATE users SET age = 20 WHERE name = 'Tom'");
    cout << "Updated " << rows << " rows." << endl;

    // 删除数据
    rows = db.execute("DELETE FROM users WHERE name = 'Tom'");
    cout << "Deleted " << rows << " rows." << endl;

    return 0;
}

注意，在运行该示例代码前，需要先安装 Microsoft ActiveX Data Objects（ADO）库，并将 `msado15.dll` 文件路径修改为本地安装路径。另外，示例代码仅供参考，实际使用时需要根据具体情况进行调整。

C++ 封装ADO连接sqlserver实现增删查改

好的，我可以给你提供一个简单的示例代码。在使用这个代码前，你需要安装并配置好ADO库。

#include <iostream>
#include <string>
#include <windows.h>
#include <comdef.h>
#include <atlbase.h>
#include <atlstr.h>
#include <stdio.h>
#include <conio.h>
#include <time.h>
#include <fstream>
#include <vector>
#include <algorithm>
#import "C:\Program Files\Common Files\System\ado\msado15.dll" no_namespace rename("EOF", "adoEOF")

using namespace std;

class ADOConnection {
private:
    _ConnectionPtr m_pConnection;
public:
    ADOConnection();
    ~ADOConnection();
    bool Open(const char* connectionString);
    bool ExecuteSQL(const char* sql);
    bool ExecuteSP(const char* spName, const char* params);
    _RecordsetPtr GetRecordset(const char* sql);
};

ADOConnection::ADOConnection() {
    HRESULT hr = m_pConnection.CreateInstance(__uuidof(Connection));
    if (FAILED(hr)) {
        _com_error err(hr);
        cerr << "CreateInstance Error: " << err.ErrorMessage() << endl;
        exit(-1);
    }
}

ADOConnection::~ADOConnection() {
    if (m_pConnection->State == adStateOpen) {
        m_pConnection->Close();
    }
}

bool ADOConnection::Open(const char* connectionString) {
    try {
        m_pConnection->Open(connectionString, "", "", adModeUnknown);
        return true;
    }
    catch (_com_error& e) {
        cerr << "Connect Error: " << e.ErrorMessage() << endl;
        return false;
    }
}

bool ADOConnection::ExecuteSQL(const char* sql) {
    try {
        m_pConnection->Execute(sql, NULL, adCmdText);
        return true;
    }
    catch (_com_error& e) {
        cerr << "ExecuteSQL Error: " << e.ErrorMessage() << endl;
        return false;
    }
}

bool ADOConnection::ExecuteSP(const char* spName, const char* params) {
    try {
        CString strCmd;
        strCmd.Format("{ call %s(%s) }", spName, params);
        m_pConnection->Execute(_bstr_t(strCmd), NULL, adCmdText | adExecuteNoRecords);
        return true;
    }
    catch (_com_error& e) {
        cerr << "ExecuteSP Error: " << e.ErrorMessage() << endl;
        return false;
    }
}

_RecordsetPtr ADOConnection::GetRecordset(const char* sql) {
    try {
        _RecordsetPtr pRecordset("ADODB.Recordset");
        pRecordset->Open(sql, m_pConnection.GetInterfacePtr(), adOpenKeyset, adLockReadOnly, adCmdText);
        return pRecordset;
    }
    catch (_com_error& e) {
        cerr << "GetRecordset Error: " << e.ErrorMessage() << endl;
        return NULL;
    }
}

这是一个基本的ADO连接类，封装了连接数据库、执行 SQL 语句和存储过程、获取记录集等常用操作，可以根据需要进行扩展。其中，`_ConnectionPtr`、`_RecordsetPtr` 等是 COM 对象的智能指针，用于自动管理对象的生命周期。

你可以在自己的代码中调用这些方法，实现对 SQL Server 数据库的增删查改操作。例如：

int main() {
    ADOConnection conn;
    if (!conn.Open("Provider=SQLOLEDB;Data Source=.;Initial Catalog=test;User ID=sa;Password=password")) {
        cerr << "Connect failed!" << endl;
        return -1;
    }
    if (!conn.ExecuteSQL("insert into mytable (name, age) values ('张三', 18)")) {
        cerr << "Insert failed!" << endl;
        return -1;
    }
    _RecordsetPtr pRecordset = conn.GetRecordset("select * from mytable");
    while (!pRecordset->adoEOF) {
        CString name = pRecordset->GetCollect("name");
        int age = pRecordset->GetCollect("age");
        cout << name << "\t" << age << endl;
        pRecordset->MoveNext();
    }
    return 0;
}

这个示例代码中包括了连接数据库、插入数据、查询数据等操作，你可以根据需要修改和扩展。