Oracle调用接口(Oracle Call Interface简称OCI)是Oracle数据库访问的基础接口。下面的例子依次执行了：
初始化OCI环境连接服务器连接数据库创建会话执行查询执行新增（更新，删除类似，不赘述）断开会话断开服务器释放资源示例代码：
ociTest.cpp
#include <oci.h> #include <iostream> #include <string> #include <string.h> #include <stdlib.h> using namespace std;
//存放查询数据的结构体 struct result { char ename[20]; char cname[20]; result() { memset(ename, '\0', sizeof(ename)); memset(cname, '\0', sizeof(cname)); } }; int main() { // 初始化 OCI 环境句柄指针 OCIEnv *envhpp = NULL; // 初始化服务器句柄 OCIServer *servhpp = NULL; // 用于捕获 OCI 错误信息 OCIError *errhpp = NULL; // 初始化会话句柄 OCISession *usrhpp = NULL; // 初始化服务上下文句柄 OCISvcCtx *svchpp = NULL; // 初始化表达式句柄 OCIStmt *stmthpp = NULL; string server="mydb"; // 创建 OCI 环境 , 并设置环境句柄。 sword swResult = OCIEnvCreate(&envhpp, OCI_DEFAULT, NULL, NULL, NULL, NULL, 0, NULL); if (swResult != OCI_SUCCESS && swResult != OCI_SUCCESS_WITH_INFO) { cout << "Oracle environment initialization error!" << endl; exit(1); } cout << "Oracle environment initialization success!" << endl; // 创建错误句柄 OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&errhpp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0); // 创建服务句柄 OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&servhpp, OCI_HTYPE_SERVER, (size_t)0, (dvoid **)0); // 连接服务器，如果失败则获取错误码 if (OCIServerAttach(servhpp, errhpp, (text *)server.c_str(), strlen(server.c_str()), 0) != OCI_SUCCESS) { int errcno; char errbuf[512] = ""; sb4 errcode; // 获取错误指针和 OCI 错误代码 OCIErrorGet((dvoid *)errhpp, (ub4)1, (text *)NULL, &errcode, (ub1 *)errbuf, (ub4)sizeof(errbuf), OCI_HTYPE_ERROR); errcno = errcode; cout << "Oracle server attach error:" << errbuf << endl; OCIHandleFree((dvoid *)envhpp,OCI_HTYPE_ENV); OCIHandleFree((dvoid *)servhpp,OCI_HTYPE_SERVER); OCIHandleFree((dvoid *)errhpp,OCI_HTYPE_ERROR); exit(1); } cout << "Oracle server attach success!"<< endl; /***************** 连接数据库 ****************/ string user = "user"; string pas = "passwd"; errhpp = NULL; // 创建错误句柄 (void) OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&errhpp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0); // 创建服务上下文句柄 (void) OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&svchpp, OCI_HTYPE_SVCCTX, (size_t) 0, (dvoid **)0); // 设置属性 (void) OCIAttrSet((dvoid *)svchpp, OCI_HTYPE_SVCCTX, (dvoid *)servhpp, (ub4)0, OCI_ATTR_SERVER, (OCIError *)errhpp); // 创建用户连接句柄 (void) OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&usrhpp, (ub4)OCI_HTYPE_SESSION, (size_t) 0, (dvoid **)0); // 设置用户名、密码 (void) OCIAttrSet((dvoid *)usrhpp, (ub4)OCI_HTYPE_SESSION, (dvoid *)user.c_str(), (ub4)strlen(user.c_str()), (ub4)OCI_ATTR_USERNAME, errhpp); (void) OCIAttrSet((dvoid *)usrhpp, (ub4)OCI_HTYPE_SESSION, (dvoid *)pas.c_str(), (ub4)strlen(pas.c_str()), (ub4)OCI_ATTR_PASSWORD, errhpp); // 创建会话连接 if(OCISessionBegin(svchpp, errhpp, usrhpp, OCI_CRED_RDBMS, (ub4)OCI_DEFAULT) != OCI_SUCCESS) { int errcno; char errbuf[512]={'\0'}; sb4 errcode; // 获取错误指针和 OCI 错误代码 OCIErrorGet((dvoid *)errhpp, (ub4)1, (text *)NULL, &errcode, (ub1 *)errbuf, (ub4)sizeof(errbuf), OCI_HTYPE_ERROR); errcno = errcode; cout << "User session error:" << errbuf << endl; OCIHandleFree((dvoid *)errhpp,OCI_HTYPE_ERROR); OCIHandleFree((dvoid *)usrhpp,OCI_HTYPE_SESSION); OCIHandleFree((dvoid *)svchpp,OCI_HTYPE_SVCCTX); exit(1); } cout << "user session success!" << endl; (void) OCIAttrSet((dvoid *)svchpp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *)usrhpp, (ub4)0, (ub4)OCI_ATTR_SESSION, errhpp); /*************** 执行 查询SQL 语句 ******************/ errhpp = NULL; // 创建一个表达式句柄 if (OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&stmthpp, OCI_HTYPE_STMT, (size_t)0, (dvoid **)0) != OCI_SUCCESS) { cout << "Create STMT error !" << endl; exit(1); } cout << "Create stmt success !" << endl; // 创建错误句柄 OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&errhpp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0); // Select语句 char sql[255] = "select col1, col2 from table1 "; if (OCIStmtPrepare(stmthpp, errhpp, (text *)sql, (ub4)strlen(sql), (ub4)OCI_NTV_SYNTAX, (ub4)OCI_DEFAULT) != OCI_SUCCESS) { cout << "Create prepare error!" << sql << endl; exit(1); } cout << "Create prepare success!" << endl; /********* 绑定参数 ***********/ // 申请绑定字段的句柄 OCIDefine *bhp1 = NULL; OCIDefine *bhp2 = NULL; // 存放数据的结构 struct result rst; // 指定提取数据长度 ub2 datalen = 0; // 定义指示器变量 , 用于取可能存在空值的字段 char isnul[6] = ""; // 定义输出变量 , OCIDefineByPos(stmthpp, &bhp1, errhpp, 1, (dvoid *)&rst.ename, sizeof(rst.ename), SQLT_CHR, NULL, &datalen, NULL, OCI_DEFAULT); OCIDefineByPos(stmthpp, &bhp2, errhpp, 2, (dvoid *)&rst.cname, sizeof(rst.cname), SQLT_STR, NULL, &datalen, NULL, OCI_DEFAULT); // 获取 SQL 语句类型 ub2 stmt_type; OCIAttrGet ((dvoid *)stmthpp, (ub4)OCI_HTYPE_STMT, (dvoid *)&stmt_type, (ub4 *)0, (ub4)OCI_ATTR_STMT_TYPE, errhpp); // 执行 SQL 语句 OCIStmtExecute(svchpp, stmthpp, errhpp, (ub4)0, (ub4)0, (OCISnapshot *)NULL, (OCISnapshot *)NULL, OCI_DEFAULT); // 获取查询信息 int rows_fetched; do { cerr << rst.ename<< " "; cerr << rst.cname<< " \n"; } while(OCIStmtFetch2(stmthpp, errhpp, 1, OCI_FETCH_NEXT, 1, OCI_DEFAULT) != OCI_NO_DATA); // 获得记录条数 OCIAttrGet((CONST void *)stmthpp, OCI_HTYPE_STMT, (void *)&rows_fetched, (ub4 *)sizeof(rows_fetched), OCI_ATTR_ROW_COUNT, errhpp); cout << " rows :" << rows_fetched << endl; /*************** 执行 新增SQL 语句 ******************/ if (OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&stmthpp, OCI_HTYPE_STMT, (size_t)0, (dvoid **)0) != OCI_SUCCESS) { cout << "Create STMT error !" << endl; exit(1); } cout << "Create stmt success !" << endl; OCIHandleAlloc((dvoid *)envhpp, (dvoid **)&errhpp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0); // Insert语句 char sql2[255] = "insert into table1 (col1, col2) values('testoci', 'testoci')"; // 准备Sql语句 if (OCIStmtPrepare(stmthpp, errhpp, (text *)sql2, (ub4)strlen(sql2), (ub4)OCI_NTV_SYNTAX, (ub4)OCI_DEFAULT) != OCI_SUCCESS) { cout << "Create prepare error!" << sql2 << endl; exit(1); } cout << "Create prepare success!" << endl; // 执行SQL 语句 OCIStmtExecute(svchpp, stmthpp, errhpp, (ub4)1, (ub4)0, (OCISnapshot *)NULL, (OCISnapshot *)NULL, OCI_DEFAULT);
// 断开用户会话 OCILogoff(svchpp, errhpp); // 断开服务器连接 OCIServerDetach(servhpp, errhpp, OCI_DEFAULT); // 释放资源 OCIHandleFree((dvoid *) stmthpp, OCI_HTYPE_STMT); OCIHandleFree((dvoid *) svchpp, OCI_HTYPE_SVCCTX); OCIHandleFree((dvoid *) servhpp, OCI_HTYPE_SERVER); OCIHandleFree((dvoid *) errhpp, OCI_HTYPE_ERROR); return 0; }
在AIX 5.0环境下编译指令： xlC -q64 -I/ora10g/app/oracle/product/10.2.0/rdbms/public -L/ora10g/app/oracle/product/10.2.0/lib -lclntsh -o ociTest ociTest.cpp 执行： ./ociTest 输出：
Oracle environment initialization success!
Oracle server attach success!
user session success!
Create stmt success !
Create prepare success!
col1 col2
rows :1
Create stmt success !
Create prepare success!
http://blog.chinaunix.net/uid-21592001-id-3271863.html
PS: 1.经在windows下测试正常，但解决中文乱码的方案并非unicode，而是NLS_LANG环境变量，如：SIMPLIFIED CHINESE_CHINA.AL32UTF8；
2.查询oracle server端的字符集 select userenv('language') from dual;
