chap13_eg5.cpp

《Oracle Spatial与OCI高级编程》相关配套源码。介绍了Oracle数据库中的两项关键开发技术Oracle Spatial以及OCI(Oracle Call Interface)。

/*
* Copyright (c) OCI高级编程
* @File name: chap13_eg5.cpp
* @Author   : He Xiong
* @Content  : 获取一个查询的结果

****/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>

#if defined(WIN32)
#pragma comment(lib, "oci.lib")
#endif

//获取错误诊断信息
//@param   : pErr,错误句柄
//           lStatus, 状态码信息
//@return  : 0: 失败，出错
//			 1: 成功返回
int CheckErr(OCIError *pErr, sword lStatus);


//数据库服务名
static text* dbname = (text*) "orcl";

//用户及密码
static text* username = (text*) "ocitest";
static text* password = (text*) "ocitest";

//DML(INSERT)操作的SQL语句
static text* select = (text*) "SELECT id, name, age, address FROM student";

static char  colname[64] = "";

int main()
{
	
	OCIEnv *envhp; // 环境句柄
	OCIServer *srvhp; //服务器句柄
	OCIError *errhp; //错误句柄
	OCIError *errhp1; //错误句柄
	OCIError *errhp2; //错误句柄
	OCISession *usrhp; //用户会话句柄
	OCISvcCtx *svchp; //服务上下文句柄
	OCIStmt* stmthp; //语句句柄

	//三个定义句柄，用于定义输出结果
	OCIDefine* defhp1;
	OCIDefine* defhp2;
	OCIDefine* defhp3;
	OCIDefine* defhp4;
	
	//输出变量
	int	nID;
	char szName[128];
	int nAge;
	char szAddress[256];
	sb2 indAddr; //address字段的指示符

	sb4 status = 0;

	ub4 colcount = 0;  //列数

	//使用线程和对象模式来创建环境句柄
	OCIEnvCreate(&envhp, OCI_THREADED|OCI_OBJECT, (dvoid *)0,
		0, 0, 0, (size_t) 0, (dvoid **)0);
	//分配服务器句柄
	OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&srvhp,
		OCI_HTYPE_SERVER, 0, (dvoid **) 0);
	//分配错误句柄
	OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&errhp,
		OCI_HTYPE_ERROR, 0, (dvoid **) 0);
	OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&errhp1,
		OCI_HTYPE_ERROR, 0, (dvoid **) 0);
	OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&errhp2,
		OCI_HTYPE_ERROR, 0, (dvoid **) 0);

	//创建服务器上下文句柄,"orcl"为建立连接的数据库名
	if (OCIServerAttach (srvhp, errhp, (text *)dbname,
		strlen ((char*)dbname), OCI_DEFAULT) == OCI_SUCCESS)
		printf("\n已经成功连上数据库orcl\n");
	else //终止程序
	{
		printf("\n数据库名字不对，连接数据库失败!\n");
		return -1;
	}
	//分配服务器上下文句柄
	OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&svchp,
		OCI_HTYPE_SVCCTX, 0, (dvoid **) 0);
	//设置服务器上下文句柄的服务器句柄属性
	OCIAttrSet ((dvoid *)svchp, OCI_HTYPE_SVCCTX,
		(dvoid *)srvhp, (ub4) 0, OCI_ATTR_SERVER, errhp);
	//分配用户会话句柄
	OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&usrhp,
		OCI_HTYPE_SESSION, 0, (dvoid **) 0);
	//为用户会话句柄设置用户名和密码属性
	OCIAttrSet ((dvoid *)usrhp, OCI_HTYPE_SESSION,
		(dvoid *)username, (ub4)strlen((char*)username),
		OCI_ATTR_USERNAME, errhp);
	OCIAttrSet ((dvoid *)usrhp, OCI_HTYPE_SESSION,
		(dvoid *)password, (ub4)strlen((char*)password),
		OCI_ATTR_PASSWORD, errhp);
	if (OCISessionBegin ( svchp, errhp, usrhp,
		OCI_CRED_RDBMS, OCI_DEFAULT) == OCI_SUCCESS)
	{
		printf("成功建立用户会话!\n");
	}
	else
	{
		printf("建立用户会话失败!\n");
		return -1;
	}
	//在服务器上下文环境中设置用户会话属性
	OCIAttrSet ( (dvoid *)svchp, OCI_HTYPE_SVCCTX,
		(dvoid *)usrhp, (ub4) 0, OCI_ATTR_SESSION, errhp);
	//分配语句句柄
	CheckErr(errhp, OCIHandleAlloc(envhp, (void**)&stmthp, OCI_HTYPE_STMT, 0, 0));

	//设置预取数量为10
	int fetchCount = 10;
	CheckErr(errhp, OCIAttrSet(stmthp, OCI_HTYPE_STMT, (void*)&fetchCount, 4, OCI_ATTR_PREFETCH_ROWS, errhp));
	//准备SQL语句
	CheckErr(errhp, OCIStmtPrepare(stmthp, errhp, select, strlen((char*)select),
		OCI_NTV_SYNTAX, OCI_DEFAULT));

	//定义输出
	CheckErr(errhp, OCIDefineByPos(stmthp, &defhp1, errhp, 1, &nID, sizeof(nID),
		SQLT_INT, 0, 0, 0, OCI_DEFAULT));
	CheckErr(errhp, OCIDefineByPos(stmthp, &defhp2, errhp, 2, szName, 33,
		SQLT_STR, 0, 0, 0, OCI_DEFAULT));
	CheckErr(errhp, OCIDefineByPos(stmthp, &defhp3, errhp, 3, &nAge, sizeof(nAge),
		SQLT_INT, 0, 0, 0, OCI_DEFAULT));
	CheckErr(errhp, OCIDefineByPos(stmthp, &defhp4, errhp, 4, szAddress, 129,
		SQLT_STR, &indAddr, 0, 0, OCI_DEFAULT));

	//提取结果
	CheckErr(errhp, OCIStmtExecute(svchp, stmthp, errhp, 0, 0, NULL, NULL,
		OCI_DEFAULT));
	printf("\n查询结果为: \n");
	printf("ID      NAME            AGE     ADDRESS\n");
	printf("---------------------------------------------------\n");
	while( OCI_NO_DATA != OCIStmtFetch(stmthp, errhp, 1, OCI_FETCH_NEXT, OCI_DEFAULT))
	{
		printf("%-8d%-16s%-8d", nID, szName, nAge);
		if(indAddr == 0) printf("%-32s", szAddress);
		printf("\n");
	}
	printf("结束会话和数据库连接!\n");
	//结束会话
	OCISessionEnd(svchp, errhp, usrhp, OCI_DEFAULT);
	//断开连接
	OCIServerDetach(srvhp, errhp, OCI_DEFAULT);
	//释放环境句柄
	OCIHandleFree((void*)envhp, OCI_HTYPE_ENV);
	int nTemp;
	scanf("%d", &nTemp);
	return 0;
}

int CheckErr(OCIError *pErr, sword lStatus)
{
    
    sb4		m_s_nErrCode = 0;
	char	m_s_szErr[512];
    
    switch (lStatus)
    {
    case OCI_SUCCESS:
        strcpy(m_s_szErr,"OCI_SUCCESS");    
        break;
    case OCI_SUCCESS_WITH_INFO:
        strcpy(m_s_szErr, "OCI_SUCCESS_WITH_INFO");
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    case OCI_ERROR:
        OCIErrorGet((dvoid *)pErr, (ub4)1, (text *)NULL, &m_s_nErrCode, 
            (unsigned char*)m_s_szErr, (ub4)sizeof(m_s_szErr), OCI_HTYPE_ERROR);
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    case OCI_NEED_DATA:
        strcpy(m_s_szErr, "OCI_NEED_DATA");
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    case OCI_NO_DATA:
        strcpy(m_s_szErr, "OCI_NO_DATA");
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    case OCI_INVALID_HANDLE:
        strcpy(m_s_szErr, "OCI_INVALID_HANDLE");
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    case OCI_STILL_EXECUTING:
        strcpy(m_s_szErr, "OCI_STILL_EXECUTING");
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    case OCI_CONTINUE:
        strcpy(m_s_szErr, "OCI_CONTINUE");
		printf("OCI Error: %s\n", m_s_szErr);
        break;
    default:
        break;
    }
    if (lStatus != OCI_SUCCESS && lStatus != OCI_SUCCESS_WITH_INFO)
    {
        return 0;  //确实有错误
    } 
    else 
    {
        return 1;  //没有检查到错误
    }
}