Red Hat Enterprise Linux AS4, C++ OCCI connect Oracle 9i

前提是已经安装好Oracle 9i。

1. 下载对应的ORACLE client安装。

http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html

因为没有9i的client提供下载了，我选择最接近的版本下载：

Version 10.1.0.5
Instant Client Package - Basic: All files required to run OCI, OCCI, and JDBC-OCI applications
Download instantclient-basic-linux32-10.1.0.5-20060511.zip (31,413,713 bytes) (cksum - 384697539)

下载之后解压。

2. 先把示例代码给出来：

//oci.cpp#include <iostream>
#include <string>
#include <occi.h>
using namespace std;
using namespace oracle::occi;

int main()
{
    Connection *conn;
    Environment *env;
    Statement *stmt;

    //build a connection
    string struser("scott");
    string strpwd("tiger");
    string strconn_string("");
    cout << "1" << endl;

    env = Environment::createEnvironment(Environment::OBJECT);
    cout << "2" << endl;

    conn = env->createConnection(struser, strpwd, strconn_string);
    cout << "3" << endl;

    if( NULL != conn)
        cout << "conn success" << endl;
    else
        cout << "conn failed" << endl;

    //execute sql statement
    string strsql("select to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss‘) from dual");
    stmt = conn->createStatement(strsql);
    ResultSet *rset = stmt->executeQuery();

    while(rset->next())
    {
        string time = rset->getString(1);
        cout << "now time:" << time << endl;
    }

    //close resourses
    stmt->closeResultSet(rset);
    conn->terminateStatement(stmt);
    env->terminateConnection(conn);
    Environment::terminateEnvironment(env);

    return 0;
}

3. 编译

这里对g++的版本有要求，如果是g++ 3.x.x的，可能会爆出如下错误：

undefined reference to `oracle::occi::Environment::createEnvironment(orac le::occi::Environment::Mode, void*, void* (*)(void*, unsigned int), void* (*)(void*, void*, unsigned int), void (*)(void*, void*))‘

网上很多讨论这个错误的，解决办法是安装低版本的g++。

If you‘re getting the following error messages:

undefined reference to `oracle:occi::Environment::createEnvironment(oracle:occi::Environment::Mode, void*, void* (*)(void*, unsigned), void* (*)(void*, void*, unsigned), void (*)(void*, void*))‘

and

undefined reference to `oracle:occi::Environment::terminateEnvironment(oracle:occi::Environment*)‘

then you‘re probably running oracle9i on redhat 8.0. to solve this, download and install the following rpm‘s from this redhat link:

* compat-gcc-7.3-2.96.118.i386.rpm
* compat-gcc-c++-7.3-2.96.118.i386.rpm
* compat-libstdc++-7.3-2.96.118.i386.rpm
* compat-libstdc++-devel-7.3-2.96.118.i386.rpm

and compile with g++296 instead of g++. sure you‘ll be stuck with g++-2.96, but at least it will compile and run.

* compat-gcc-7.3-2.96.118.i386.rpm
* compat-libstdc++-7.3-2.96.118.i386.rpm
* compat-libstdc++-devel-7.3-2.96.118.i386.rpm 
* compat-gcc-c++-7.3-2.96.118.i386.rpm

请按照安装上述顺序安装rpm包，因为最后一个依赖于第一二三个。

如果安装的时候报错说“正在安装的g++与系统上存在的g++有冲突”，在rpm后加上-aid --force参数，如下：

sudo rpm -ivh xxx.rpm -aid --force

详情可见这篇文：http://www.cnblogs.com/duanguyuan/p/4118210.html

安装好此版本的g++后，就可以用以下命令编译了：

 g++296 -o oci -I /opt/oracle/product/rdbms/public/ -I /opt/oracle/product/rdbms/demo/ -I /home/oracle/instantclient10_1/ -L /opt/oracle/product/lib/ -L /opt/oracle/product/rdbms/lib/ oci.cpp -lclntsh -locci /usr/lib/libstdc++.so.5 -Wall -O -g

注意仔细看上边所包含的编译目录，先看看自己的$ORACLE_HOME在哪里，看看上述的目录都在不在。其中instantclient10_1目录便是第一步下载的Oracle client。

4. 运行

结果如下图

其他参考：

http://blog.csdn.net/gyanp/article/details/6107044

http://oradim.blogspot.com/2009/08/getting-started-with-occi-linux-version.html