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C++与Oracle数据库的事务处理

小樊
84
2024-09-02 09:03:53
栏目: 云计算

C++ 与 Oracle 数据库的事务处理涉及到使用 C++ 编程语言与 Oracle 数据库进行交互,以实现事务的提交、回滚等操作。以下是一个简单的示例,展示了如何在 C++ 中使用 OCI(Oracle Call Interface)库来处理 Oracle 数据库的事务。

首先,确保已经安装了 Oracle Instant Client,并正确配置了环境变量。然后,创建一个名为 “example.cpp” 的文件,并添加以下代码:

#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;
}

将上述代码中的 sql_stmt 变量替换为要执行的 SQL 语句。编译并运行示例代码,它将连接到本地 Oracle 数据库,开始一个事务,执行 SQL 语句,提交或回滚事务,然后断开连接并进行清理。

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