java查询数据库返回结果 java查询数据库返回值

     这里使用Oracle数据库的thin连接。

     下面是存储过程SQL

View Procedure(查看存储过程)

1 createorreplaceprocedure proc3(stid in student.stuid%type, stname out student.sname%type, stphone out student.phonenumber%type, stuadd out student.saddress%type)
 2 as countnumber number;
 3 begin
 4 selectcount(*) into countnumber from student where stuid=stid;
 5 if countnumber=1then
 6 select phonenumber into stphone from student where stuid=stid;
 7 select saddress into stuadd from student where stuid=stid;
 8 select sname into stname from student where stuid=stid;
 9 else
10          dbms_output.put_line('返回值过多');
11 endif;
12 end;

prepareCall 方法。结构：{call 存储过程名(?,?,...)}

在设置参数的时候，输入参数用set，输出参数要registerOutParameter。取出输出参数的值可以直接用CallabelStatement的get方法

 

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

public class Dao {

    String driver="oracle.jdbc.driver.OracleDriver";
    String url="jdbc:oracle:thin:@127.0.0.1:1521:orcl";
    Connection conn=null;
    CallableStatement cs=null;//PreparedStatement,Statement
    ResultSet rs;


public void getConn(){
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, "scott", "tiger");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }
public void callProc(){
        try {
            cs = conn.prepareCall("{call proc3(?,?,?,?)}");
            cs.setInt(1, 1);
            cs.registerOutParameter(2, Types.VARCHAR);
            cs.registerOutParameter(3, Types.VARCHAR);
            cs.registerOutParameter(4, Types.VARCHAR);
            cs.execute();
            String name = cs.getString(2);
            String phone = cs.getString(3);
            String address = cs.getString(4);
            System.out.println("Name:"+name+"\t Phone:"+phone+"\t Address:"+address);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            try {
if (cs!=null) cs.close();
if(conn!=null) conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
public static void main(String[] args) {
        Dao dao = new Dao();
        dao.getConn();
        dao.callProc();
    }
}

       以上方法只支持返回个别数据的，不能像SQL返回结果集类型那样。其实，Oracle并不能直接用存储过程来返回结果集，需要借用包才能实现。看代码：

1 CREATEORREPLACE PACKAGE mypack IS
2     TYPE mycursor IS REF CURSOR;
3 PROCEDURE myproc(outcursor IN OUT mycursor);
4 END mypack;

这里建了一个包，其中有两个元素：mycursor游标和myproc存储过程。执行该语句之后要再定义这个包中的内容，代码如下：

1 CREATEORREPLACE PACKAGE BODY mypack IS
 2 PROCEDURE myproc(
 3         outcursor IN OUT mycursor
 4     )
 5 IS
 6 BEGIN
 7 OPEN outcursor FOR
 8 SELECT*FROM Student WHERE ROWNUM<10;
 9 RETURN;
10 END myproc;
11 END;

这里详细定义了mycursor和myproc的body。注意：CREATE PACKAGE和CREATE PACKAGE BODY不能一起执行，必须先后执行，否则会报错(用goto;连接是可以的)。OKay，包和存储过程定义好了，该写Java代码了：

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

import oracle.jdbc.OracleTypes;

publicclass Dao {

    String driver="oracle.jdbc.driver.OracleDriver";
    String url="jdbc:oracle:thin:@127.0.0.1:1521:orcl";
    Connection conn=null;
    CallableStatement cs=null;//PreparedStatement,Statement
    ResultSet rs;

publicvoid getConn(){
try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, "scott", "tiger");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
publicvoid callProc(){
try {
            cs = conn.prepareCall("{call proc3(?,?,?,?)}");
            cs.setInt(1, 1);
            cs.registerOutParameter(2, Types.VARCHAR);
            cs.registerOutParameter(3, Types.VARCHAR);
            cs.registerOutParameter(4, Types.VARCHAR);
            cs.execute();
            String name = cs.getString(2);
            String phone = cs.getString(3);
            String address = cs.getString(4);
            System.out.println("Name:"+name+"\t Phone:"+phone+"\t Address:"+address);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
publicvoid callProcForResult(){
try {
            cs = conn.prepareCall("{call mypack.myproc(?)}");
            cs.registerOutParameter(1, OracleTypes.CURSOR);
            cs.execute();
            ResultSet rs = (ResultSet)cs.getObject(1);
while(rs!=null&& rs.next()){
                System.out.println(new StringBuilder("ID:").append(rs.getInt(1)).append("\t Name:").append(rs.getString(2))
                    .append("\t Phone:").append(rs.getString(6)).append("\t Address:").append(rs.getString(7)).toString());
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
publicvoid closeConn(){
try {
if (cs!=null) cs.close();
if(conn!=null) conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
publicstaticvoid main(String[] args) {
        Dao dao =new Dao();
        dao.getConn(); //得到连接
        dao.callProc(); //调用返回单属性的存储过程
        dao.callProcForResult(); //调用返回结果集的存储过程
        dao.closeConn(); //关闭连接
    }
}