用java连接Oracle数据库进行简单的查询

用sys登录进sql plus
创建用户
create user 用户 identified by 密码;
授权
grant connect,resource to 用户；
grant selet any dictionary to 用户;
grant OEM_MONITOR to 用户;
grant create any view to grant create any view to jk028;;

以jk...登录到sql plus上
conn jk...;
create table jk028.Student
(
Sno nvarchar2(16) not null,
Name nvarchar2(6),
Sex nchar(1),
Age smallint,
IdCard nvarchar2(20),
PoliticalStatus nvarchar2(6),
constraint pk_Sno primary key(Sno)
);

create table jk028.Course
(
Cno nvarchar2(16) not null,
CourseName nvarchar2(18),
Credit smallint,
constraint pk_Cno primary key(Cno)
);

create table jk028.SelectCourse
(
Sno nvarchar2(16) not null,
Cno nvarchar2(16) not null,
Score int,
constraint fk_Sno foreign key(Sno) references jk028.Student(Sno),
constraint fk_Cno foreign key(Cno) references jk028.Course(Cno)
);

create view jk028.V_学生成绩
as
select s.Sno,s.Name,s.Sex,s.IdCard,c.CourseName,c.Credit,sc.Score
from jk028.SelectCourse sc join jk028.Student s on sc.Sno=s.Sno join jk028.Course c on sc.Cno=c.Cno;

添加数据：
Student

insert into jk028.Student values('1060315014001','王1','男',20,'610203199701192911','共青团员');
insert into jk028.Student values('1060315014002','王2','女',20,'610203199701192912','共青团员');
insert into jk028.Student values('1060315014003','王3','男',20,'610203199701192913','共青团员');
insert into jk028.Student values('1060315014004','王4','女',20,'610203199701192914','共青团员');
insert into jk028.Student values('1060315014005','王5','男',20,'610203199701192915','共青团员');

Course

insert into jk028.Course values('0001','数据库',11);
insert into jk028.Course values('0002','马克思原理',12);
insert into jk028.Course values('0003','数据挖掘',13);
insert into jk028.Course values('0004','软件工程',14);
insert into jk028.Course values('0005','操作系统',15);

SelectCourse

insert into jk028.SelectCourse values('1060315014001','0001',91);
insert into jk028.SelectCourse values('1060315014002','0001',91);
insert into jk028.SelectCourse values('1060315014003','0001',91);
insert into jk028.SelectCourse values('1060315014004','0001',91);
insert into jk028.SelectCourse values('1060315014005','0001',91);

先将外部jar引入到项目文件中 将Oracle/product/11.2.0//db_home/jdbc/lib中的ojdbc6文件引入

package oraclework;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class ConnOracle {

private static Connection con ;
private static String user = "jk028" ; //数据库账号
private static String password = "123456" ;// 数据库密码
private static String className = "oracle.jdbc.driver.OracleDriver" ;
private static String url = "jdbc:oracle:thin:@127.0.0.1:1521:Oraclewk" ; //"jdbc:oracle:thin:@127.0.0.1:1521:Oraclewk"
br/>//"jdbc:oracle:thin:@127.0.0.1:1521:Oraclewk"
//hostname: XL2LY877TNOBUUF
public static void main(String[] args) {
// TODO Auto-generated method stub
ConnOracle c = new ConnOracle();
c.ConnectOracle();
c.getCon();
c.closed();
}
public static ResultSet select(String sql){

ConnectOracle();
Connection conn=getCon();
ResultSet rs=null;
PreparedStatement pre=null;
try {
    pre=conn.prepareStatement(sql);;
    rs=pre.executeQuery(sql);
} catch (SQLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}     
return rs;
}
public static void ConnectOracle() {  
       try {  
             Class. forName(className);  
             System. out.println("加载数据库驱动成功！" );  
      } catch (ClassNotFoundException e ) {  
             System. out.println("加载数据库驱动失败！" );  
              e.printStackTrace();  
      }  

}

/** 创建数据库连接 */  
public static Connection getCon() {  
       try {  
              con = DriverManager. getConnection(url, user, password);  
             System. out.println("创建数据库连接成功！" );  
      } catch (SQLException e ) {  
             System. out.print(con );  
             System. out.println("创建数据库连接失败！" );  
              con = null;  
              e.printStackTrace();  
      }  
       return con ;  

}

public static void closed() {  
       try {  
              if (con != null) {  
                    con.close(); 
                    System.out.println("关闭数据库连接成功！");
             }  
      } catch (SQLException e ) {  
             System. out.println("关闭con对象失败！" );  
              e.printStackTrace();  
      }  

}
}

package oraclework;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;

public class StudentSelectCourse {
public static void main(String[] args) throws SQLException {
StudentSelectCourse ssc=new StudentSelectCourse();
String sql1="select from jk028.Student";
String sql2="select from jk028.Course";
String sql3="select * from jk028.V_学生成绩";
ssc.sqlselect(sql1);
ssc.sqlselect(sql2);
ssc.sqlselect(sql3);
}
public void sqlselect(String sql) throws SQLException{

  ResultSet rs=ConnOracle.select(sql);//学生表      
  try {
    while(rs.next()){
        int i=1;
         while(rs.getMetaData().getColumnCount()>=i){//列数
             System.out.print(rs.getNString(i++)+"\t");
         }
         System.out.println();
    }

} catch (SQLException e) {
    e.printStackTrace();
}
 rs.close();
 ConnOracle.closed();
}

}