jdbc简单应用

package com;


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

public class TestJDBC4 {
	/**
	 * @param args
	 */
	Connection conn = null;
	PreparedStatement pstmt=null;
	ResultSet rs=null;	
	public static void main(String[] args) {

//		insert();
//		new TestJDBC4().update();
		new TestJDBC4().select();
	}
	public  void select (){
		init(); 
		try{
		String sql="select * from emp where deptno = ?";
		 pstmt=conn.prepareStatement(sql);
		 //1:第一个问号的位置，10表示第一个问号的数值
		 pstmt.setInt(1, 10);
		 rs=pstmt.executeQuery();
		 
		 while(rs.next()){
			 System.out.print(rs.getString("ename")+"\t");
			 System.out.println(rs.getString("deptno"));
		 }
		 close();
		}catch(Exception e){e.printStackTrace();}
	}
	public  void insert(){
	init();
	try{
		String sql="insert  into dept values(?,?,?)";
		pstmt=conn.prepareStatement(sql);
		pstmt.setInt(1, 11);
		pstmt.setString(2, "guanliyingxiao");
		pstmt.setString(3, "home");
		 int n=pstmt.executeUpdate();
		 if(n==1){
			 System.out.println("Ok");
		 }else{
			 System.out.println("false");
		 }
		 close();
	}catch(Exception e){
		e.printStackTrace();
	}
}

	public  void delete(){
		String sql="delete dept  where deptno=?";
		/***/
	}
	
	public  void update(){
		init();
		try {
			String sql="update dept set loc=? where deptno=?";
			 pstmt=conn.prepareStatement(sql);
			 pstmt.setString(1," xuexiao");
			 pstmt.setInt(2, 11);
			int k=pstmt.executeUpdate();
			System.out.println(k+"条记录被更改");
			System.out.println((k>0)?"ok":"error");
			 close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	public  void init(){
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
		String url="jdbc:oracle:thin:@10.12.36.201:1521:xxxxxx";
		String dbUsername="scott";
		String dbPassword="tiger";
		 conn=DriverManager.getConnection(url, dbUsername, dbPassword);
		}catch(Exception e){e.printStackTrace();}
	}
	public  void close(){
				try {
					if(rs!=null){
					rs.close();}
				} catch (SQLException e) {
					e.printStackTrace();
				}
				try {
					if(pstmt!=null){
					pstmt.close();}
				} catch (SQLException e) {
					e.printStackTrace();
				}
				try {
					if(conn!=null){
					conn.close();}
				} catch (SQLException e) {
					e.printStackTrace();
				}
	}
}