c oracle 类

C语言是一种非常流行的编程语言，它能够通过访问系统硬件资源来提高程序的效率。而Oracle是一种流行的关系型数据库，它被广泛应用于企业级软件开发。当这两个强大的软件工具结合在一起，便形成了C Oracle类，它可以让您通过C语言访问Oracle数据库。以下是对C Oracle类的详细介绍。

假设有一个存储学生信息的Oracle表，我们需要用C语言代码查询这个表，并将结果输出到控制台。为了做到这一点，我们需要使用C Oracle类来连接到数据库并执行查询操作。下面是一段示例代码：

#include#includeint main() { OCIEnv *envhp; OCIError *errhp; OCIServer *srvhp; OCISvcCtx *svchp; OCISession *authp; OCIStmt *stmtp; OCIDefine *defnp; sword status; text *username = (text *)"larry"; text *password = (text *)"password"; text *sql = (text *)"SELECT * FROM students;"; int sid, age; text name[32]; /* 初始化OCI环境 */ OCIInitialize(OCI_DEFAULT, (dvoid *)0, (dvoid * (*)(dvoid *, size_t))0, (dvoid * (*)(dvoid *, dvoid *, size_t))0, (void (*)(dvoid *, dvoid *))0 ); OCIEnvInit(&envhp, OCI_DEFAULT, 0, (dvoid **)0); /* 创建OCI连接 */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&errhp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&srvhp, OCI_HTYPE_SERVER, (size_t)0, (dvoid **)0); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&svchp, OCI_HTYPE_SVCCTX, (size_t)0, (dvoid **)0); OCIServerAttach(srvhp, errhp, (text *)"ORCL", strlen("ORCL"), 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)srvhp, (ub4)0, OCI_ATTR_SERVER, errhp); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&authp, OCI_HTYPE_SESSION, (size_t)0, (dvoid **)0); /* 连接数据库 */ OCISessionBegin(svchp, errhp, authp, OCI_CRED_RDBMS, OCI_DEFAULT); OCIAttrSet((dvoid *)authp, OCI_HTYPE_SESSION, (dvoid *)username, strlen((char *)username), OCI_ATTR_USERNAME, errhp); OCIAttrSet((dvoid *)authp, OCI_HTYPE_SESSION, (dvoid *)password, strlen((char *)password), OCI_ATTR_PASSWORD, errhp); OCISessionGet(svchp, errhp, authp, (OCISvcCtx **)&svchp, (dvoid **)0, (dvoid **)0, (ub4)0); /* 执行查询 */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmtp, OCI_HTYPE_STMT, (size_t)0, (dvoid **)0); OCIStmtPrepare(stmtp, errhp, sql, strlen((char *)sql), OCI_NTV_SYNTAX, OCI_DEFAULT); OCIExecute(svchp, stmtp, errhp, (ub4)1, (ub4)0, (const OCISnapshot *)0, (OCISnapshot *)0, OCI_DEFAULT); /* 获取查询结果 */ OCIDefineByPos(stmtp, &defnp, errhp, (ub4)1, (dvoid *)name, (sb4)sizeof(name), SQLT_STR, (dvoid *)0, (ub2 *)0, (ub2 *)0, OCI_DEFAULT); OCIDefineByPos(stmtp, &defnp, errhp, (ub4)2, (dvoid *)&sid, (sb4)sizeof(sid), SQLT_INT, (dvoid *)0, (ub2 *)0, (ub2 *)0, OCI_DEFAULT); OCIDefineByPos(stmtp, &defnp, errhp, (ub4)3, (dvoid *)&age, (sb4)sizeof(age), SQLT_INT, (dvoid *)0, (ub2 *)0, (ub2 *)0, OCI_DEFAULT); while ((status = OCIFetch(stmtp)) != OCI_NO_DATA) { printf("Name: %s, SID: %d, Age: %d\n", name, sid, age); } /* 断开与数据库的连接 */ OCILogoff(svchp, errhp); OCIHandleFree((dvoid *)stmtp, OCI_HTYPE_STMT); return 0; }