每天学习3

Posted 2020-11-05 zwj-199306231519

[cpp] view plain copy
#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;
}