OCCI数据库Oracle编程步骤
1.配置环境
(1)Occi访问数据库需要occi.h头文件,此文件在oracle安装目录下,必须有oracle库的支持。安装oracle服务端或客户端;
(2)配置NLS_LANG环境变量,必须与数据库的字符编码一致,否则可能出现中文乱码;
(3)配置环境变量,使客户端支持中文显示;
(4)安装C++编程工具和g++编译工具。
2.编写C++程序
(1)Environment类创建occi环境变量;
(2)Environment类下的createConnection方法创建连接数据库的Connection对象;
(3)Statement类创建对象,由数据库连接对象调用createStatement方法创建;
(4)Statement类创建对象调用setSQL()准备SQL语句;
(5)Statement类创建对象调用execute()或executeUpdate()或executeQurey()或executeArrayUpdate()方法执行查询,如果是查询的,创建ResultSet对象接收数据集;如果是数据更新回插入:Statement:: setAutoCommit (TRUE); 设置自动提交;Statement::setAutoCommit(FALSE); 设置手动提交,手动提交:Connection::commit();Connection::rollback();
(6)Statement类创建对象调用getxxx()方法获取字段数据;
(7)terminateStatement()终止Statement对象;
(8)terminateConnection()断开数据库连接;
(9)Environment::terminateEnvironment()终止环境变量。
- #include<iostream>
- #include<occi.h>//occi头文件
- //声明命名空间
- usingnamespaceoracle::occi;
- usingnamespacestd;
- intmain()
- {
- Environment*env;
- Connection*conn;
- Statement*stmt;
- ResultSet*rs;
- stringusername="system";//用户名
- stringpassword="st1234";//密码
- stringconnstring="orcl";//数据库连接字符串
- stringsql,strname;
- intisno;
- env=Environment::createEnvironment();//创建环境变量
- conn=env->createConnection(username,password,connstring);//创建数据库连接对象
- stmt=conn->createStatement();//创Statement对象
- sql="SELECTu_id,u_name,to_char(u_date,'yyyy-mm-ddhh24:mi:ss')FROMstudent";
- stmt->setSQL(sql);//准备SQL语句
- try
- {
- rs=stmt->executeQuery();//执行SQL语句,返回结果集
- while(rs->next())//取数据
- {
- isno=rs->getInt(1);
- strname=rs->getString(2);
- cout<<isno<<"AND"<<strname<<endl;
- cout<<rs->getString(3)<<endl;
- }
- cout<<"SELECTSUCCESS"<<endl;
- }
- catch(SQLExceptionex)//异常处理
- {
- cout<<"ErrorNumber"<<ex.getErrorCode()<<endl;
- cout<<ex.getMessage()<<endl;
- }
- conn->terminateStatement(stmt);//终止Statement对象
- env->terminateConnection(conn);//断开数据库连接
- Environment::terminateEnvironment(env);//终止环境变量
- return1;
- }
3.编写makefile文件
Makefile:
includepath=${ORACLE_HOME}/rdbms/public
libpath=${ORACLE_HOME}/lib
libfile=-L ${libpath} -locci -lclntsh /usr/lib/libstdc++.so.5
incfile=-I ${includepath}
occiselect:select.cpp
g++ -o occiselect select.cpp ${libfile} ${incfile}
clean:
rm occiselect
4.编译程序
Make occiselect.