c 访问oracle

在计算机领域，C语言是一种很流行的编程语言，可用于开发一系列基于计算机的应用程序。同时，Oracle是目前最大最强的关系数据库管理系统之一，已经广泛应用于企业级应用程序开发。因此，使用C语言访问Oracle数据库也是一种非常有力的工具，本文将介绍关于C语言访问Oracle的相关技术和方法。

使用C语言访问Oracle需要使用Oracle提供的OCI库。OCI（Oracle Call Interface）是Oracle数据库提供的一套C语言接口函数库，可以方便地实现与Oracle数据库之间的交互。以下是一个简单的示例代码：

#include#includeint main() { OCIEnv * envhp = (OCIEnv *)0; OCIError * errhp = (OCIError *)0; OCISvcCtx * svchp = (OCISvcCtx *)0; OCIStmt * stmthp = (OCIStmt *)0; text * username = (text *)"scott"; text * password = (text *)"tiger"; text * dbname = (text *)"orcl"; int res = 0; /*初始化OCI环境*/ OCIInitialize((ub4) OCI_THREADED, (dvoid *)0, (dvoid * (*)(dvoid *, size_t)) 0, (dvoid * (*)(dvoid *, dvoid *, size_t))0, (void (*)(dvoid *, dvoid *)) 0 ); OCIEnvInit( (OCIEnv **) &envhp, OCI_DEFAULT, (size_t) 0, (dvoid **) 0 ); /*登陆数据库*/ OCIHandleAlloc((dvoid*) envhp, (dvoid **)&errhp, (ub4) OCI_HTYPE_ERROR, (size_t) 0, (dvoid**) 0); OCILogon(envhp, errhp, &svchp, username, strlen((char*)username), password, strlen((char*)password), dbname, strlen((char*)dbname)); /*创建查询语句*/ OCIHandleAlloc((dvoid*) envhp, (dvoid **)&stmthp, (ub4) OCI_HTYPE_STMT, (size_t) 0, (dvoid **) 0); res = OCIStmtPrepare(stmthp, errhp, (text *)"SELECT * FROM emp", (ub4)strlen("SELECT * FROM emp"), (ub4)OCI_NTV_SYNTAX, (ub4)OCI_DEFAULT); /*执行查询语句*/ res = OCIStmtExecute(svchp, stmthp, errhp, (ub4)0, (ub4)0, (CONST OCISnapshot*)NULL, (OCISnapshot*)NULL, OCI_DEFAULT); /*输出查询结果*/ while (OCIStmtFetch(stmthp, errhp, 1, OCI_FETCH_NEXT, OCI_DEFAULT) == OCI_SUCCESS) { printf("empno=%d, ename=%s, job=%s, sal=%f\n", empno, ename, job, sal); } /*释放OCI句柄*/ OCIHandleFree((dvoid *)stmthp, (ub4)OCI_HTYPE_STMT); OCIHandleFree((dvoid *)errhp, (ub4)OCI_HTYPE_ERROR); OCILogoff(svchp, envhp, errhp); OCIHandleFree((dvoid *)envhp, (ub4)OCI_HTYPE_ENV); return 0; }