C++ 與 Oracle 數據庫的事務處理涉及到使用 C++ 編程語言與 Oracle 數據庫進行交互，以實現事務的提交、回滾等操作。以下是一個簡單的示例，展示了如何在 C++ 中使用 OCI（Oracle Call Interface）庫來處理 Oracle 數據庫的事務。

首先，確保已經安裝了 Oracle Instant Client，并正確配置了環境變量。然后，創建一個名為 “example.cpp” 的文件，并添加以下代碼：

#include <iostream>
#include <oci.h>

using namespace std;

void handleError(const char *msg) {
    cout << msg << endl;
    exit(-1);
}

int main() {
    OCIEnv *env = nullptr, *errhp = nullptr;
    OCIServer *srvhp = nullptr;
    OCISvcCtx *svchp = nullptr;
    OCIAttrSet(env, (dvoid *)OCI_HTYPE_ENV, (dvoid *)errhp, 0, (dvoid *)OCI_ATTR_ERROR, env);
    OCIAttrSet(env, (dvoid *)OCI_HTYPE_SERVER, (dvoid *)srvhp, 0, (dvoid *)OCI_ATTR_SERVER, env);
    OCIAttrSet(env, (dvoid *)OCI_HTYPE_SVCCTX, (dvoid *)svchp, 0, (dvoid *)OCI_ATTR_SVCCTX, env);

    if (OCIInit(&env, errhp, NULL, NULL, NULL) != OCI_SUCCESS) {
        handleError("OCIInit failed");
    }

    if (OCIServerAttach(srvhp, errhp, (OraText *)"localhost:1521", strlen("localhost:1521"), 0) != OCI_SUCCESS) {
        handleError("OCIServerAttach failed");
    }

    if (OCIHandleAlloc((dvoid *)env, (dvoid **)&svchp, OCI_HTYPE_SVCCTX, 0, NULL) != OCI_SUCCESS) {
        handleError("OCIHandleAlloc failed");
    }

    if (OCIAttrSet(svchp, (dvoid *)OCI_HTYPE_SVCCTX, (dvoid *)srvhp, 0, (dvoid *)OCI_ATTR_SERVER, svchp) != OCI_SUCCESS) {
        handleError("OCIAttrSet failed");
    }

    if (OCIHandleAlloc((dvoid *)env, (dvoid **)&errhp, OCI_HTYPE_ERROR, 0, NULL) != OCI_SUCCESS) {
        handleError("OCIHandleAlloc failed");
    }

    if (OCIStartup(svchp, errhp) != OCI_SUCCESS) {
        handleError("OCIStartup failed");
    }

    // Begin transaction
    if (OCIHandleBegin((dvoid *)svchp, errhp, OCI_DEFAULT) != OCI_SUCCESS) {
        handleError("OCIHandleBegin failed");
    }

    // Execute SQL statements
    if (OCIHandleExecute(svchp, errhp, (dvoid *)sql_stmt, strlen(sql_stmt), 0, NULL, 0, NULL, OCI_DEFAULT) != OCI_SUCCESS) {
        handleError("OCIHandleExecute failed");
    }

    // Commit transaction
    if (OCIHandleCommit((dvoid *)svchp, errhp, OCI_DEFAULT) != OCI_SUCCESS) {
        handleError("OCIHandleCommit failed");
    } else {
        cout << "Transaction committed successfully." << endl;
    }

    // Rollback transaction
    if (OCIHandleRollback((dvoid *)svchp, errhp, OCI_DEFAULT) != OCI_SUCCESS) {
        handleError("OCIHandleRollback failed");
    } else {
        cout << "Transaction rolled back successfully." << endl;
    }

    // Disconnect and cleanup
    OCIHandleFree(svchp);
    OCIHandleFree(errhp);
    OCIHandleFree(srvhp);
    OCIShutdown(env);

    return 0;
}

將上述代碼中的 sql_stmt 變量替換為要執行的 SQL 語句。編譯并運行示例代碼，它將連接到本地 Oracle 數據庫，開始一個事務，執行 SQL 語句，提交或回滾事務，然后斷開連接并進行清理。