怎样在C++中执行SQL事务？

#include <iostream>
#include <sql.h>
#include <sqlext.h>
#include <string>

int main() {
    SQLHENV env;
    SQLHDBC dbc;
    SQLHSTMT stmt;
    SQLRETURN ret;

    // 初始化环境
    SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
    SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);

    // 连接到数据库
    SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
    std::string connStr = "DRIVER={SQL Server};SERVER=localhost;DATABASE=myDB;UID=user;PWD=password;";
    ret = SQLDriverConnect(dbc, NULL, (SQLCHAR*)connStr.c_str(), SQL_NTS, NULL, 0, NULL, SQL_DRIVER_NOPROMPT);

    if (SQL_SUCCEEDED(ret)) {
        // 分配语句句柄
        SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);

        // 开始事务
        SQLSetConnectAttr(dbc, SQL_ATTR_AUTOCOMMIT, (SQLPOINTER)SQL_AUTOCOMMIT_OFF, 0);

        // 执行SQL语句
        std::string sql1 = "INSERT INTO Users (Name, Age) VALUES ('John Doe', 30)";
        ret = SQLExecDirect(stmt, (SQLCHAR*)sql1.c_str(), SQL_NTS);

        if (SQL_SUCCEEDED(ret)) {
            std::string sql2 = "UPDATE Users SET Age = 31 WHERE Name = 'John Doe'";
            ret = SQLExecDirect(stmt, (SQLCHAR*)sql2.c_str(), SQL_NTS);

            if (SQL_SUCCEEDED(ret)) {
                // 提交事务
                SQLEndTran(SQL_HANDLE_DBC, dbc, SQL_COMMIT);
                std::cout << "Transaction committed successfully." << std::endl;
            } else {
                // 回滚事务
                SQLEndTran(SQL_HANDLE_DBC, dbc, SQL_ROLLBACK);
                std::cout << "Transaction rolled back due to error." << std::endl;
            }
        } else {
            // 回滚事务
            SQLEndTran(SQL_HANDLE_DBC, dbc, SQL_ROLLBACK);
            std::cout << "Transaction rolled back due to error." << std::endl;
        }

        // 释放语句句柄
        SQLFreeHandle(SQL_HANDLE_STMT, stmt);
    } else {
        std::cout << "Failed to connect to the database." << std::endl;
    }

    // 断开连接并释放环境
    SQLDisconnect(dbc);
    SQLFreeHandle(SQL_HANDLE_DBC, dbc);
    SQLFreeHandle(SQL_HANDLE_ENV, env);

    return 0;
}