C语言中Oracle事务的有效管理（c 中 oracle事务）

C语言中Oracle事务的有效管理

在C语言中，如果要与数据库进行交互，Oracle就是一种常见的数据库管理系统。而事务的管理在数据的读写中是非常重要的。下面，我们来探讨一下在C语言中，如何有效地管理Oracle事务。

在使用Oracle数据库时，我们需要引入Oracle相关的头文件。其中，oracle.h用于定义Oracle数据库连接所需的结构、对象、类型和变量；sqlca.h则是Oracle数据库操作的错误处理头文件。代码如下：

#include 
#include 
#include 
#include 
#include 

我们需要在程序中进行初始化和连接Oracle服务器，包括创建OCIEnv环境句柄和OCIError错误句柄等。具体代码如下：

OCIEnv *envhp;
OCIError *errhp;
OCIServer *srvhp;
OCISession *usrhp;
OCIStmt *stmthp;
//初始化环境句柄和错误句柄
if (OCIEnvCreate(&envhp, OCI_DEFAULT, NULL, NULL, NULL, NULL, 0, NULL)) {
    printf("Error creating the environment handle.\n");
    exit(EXIT_FLURE);
}
if (OCIHandleAlloc(envhp, (dvoid **)&errhp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0)) {
    printf("Error allocating the error handle.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    exit(EXIT_FLURE);
}
//创建服务器句柄
if (OCIHandleAlloc(envhp, (dvoid **)&srvhp, OCI_HTYPE_SERVER, (size_t)0, (dvoid **)0)) {
    printf("Error allocating server handle.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}
//连接Oracle服务器
if (OCILogon(envhp, errhp, &srvhp, (CONST text *)"username", (ub4)strlen("username"), (CONST text *)"password", (ub4)strlen("password"), (CONST text *)"server", (ub4)strlen("server"))) {
    printf("Error logging on.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}
//创建用户会话句柄
if (OCIHandleAlloc(envhp, (dvoid **)&usrhp, OCI_HTYPE_SESSION, (size_t)0, (dvoid **)0)) {
    printf("Error allocating user session handle.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}
//设置用户会话句柄的服务器句柄和用户名
if (OCIAttrSet((dvoid *)usrhp, OCI_HTYPE_SESSION, (dvoid *)srvhp, (ub4)0, OCI_ATTR_SERVER, errhp)) {
    printf("Error setting server attribute.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}
if (OCIAttrSet((dvoid *)usrhp, OCI_HTYPE_SESSION, (dvoid *)"username", (ub4)strlen("username"), OCI_ATTR_USERNAME, errhp)) {
    printf("Error setting username attribute.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}

//开始会话
if (OCISessionBegin(srvhp, errhp, usrhp, OCI_CRED_RDBMS, OCI_DEFAULT)) {
    printf("Error beginning session.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}

在连接Oracle服务器之后，我们可以开始进行事务的管理。其中，事务的开始和提交非常关键，代码如下：

//开始事务
if (OCIHandleAlloc(envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, (size_t)0, (dvoid **)0)) {
    printf("Error allocating statement handle.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCISessionEnd(srvhp, errhp, usrhp, OCI_DEFAULT);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}

OCIError *tperrhp;
if (OCIHandleAlloc(envhp, (dvoid **)&tperrhp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0)) {
    printf("Error allocating transaction error handle.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCISessionEnd(srvhp, errhp, usrhp, OCI_DEFAULT);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}
if (OCIAttrSet((dvoid *)stmthp, OCI_HTYPE_STMT, (dvoid *)&tperrhp, 0, OCI_ATTR_TRANS_COR, tperrhp)) {
    printf("Error setting transaction context.\n");
    OCIHandleFree(envhp, (dvoid *)tperrhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)stmthp, OCI_HTYPE_STMT);
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCISessionEnd(srvhp, errhp, usrhp, OCI_DEFAULT);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}

if (OCIHandleAlloc(envhp, (dvoid **)&tperrhp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0)) {
    printf("Error allocating transaction error handle.\n");
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCISessionEnd(srvhp, errhp, usrhp, OCI_DEFAULT);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    return 0;
}

//打开事务
if (OCITransStart(envhp, tperrhp, (uword)0, OCI_TRANS_READWRITE)) {
    printf("Error starting transaction.\n");
    OCIHandleFree(envhp, (dvoid *)tperrhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)stmthp, OCI_HTYPE_STMT);
    OCIHandleFree(envhp, (dvoid *)errhp, OCI_HTYPE_ERROR);
    OCIHandleFree(envhp, (dvoid *)usrhp, OCI_HTYPE_SESSION);
    OCISessionEnd(srvhp, errhp, usrhp, OCI_DEFAULT);
    OCIHandleFree(envhp, (dvoid *)srvhp, OCI_HTYPE_SERVER);
    OCIHandleFree(envhp, (dvoid *)envhp, OCI_HTYPE_ENV);
    exit(EXIT_FLURE);
}
//执行SQL语句
if (OCIStmtPrepare(stmthp, errhp, (CONST text *)"UPDATE table SET column = ?", (ub4)strlen("UPDATE table SET column = ?"), OCI_NTV_SYNTAX,