编写一个java程序，通过jdbc访问数据库实现对数据库的插入，删除，修改和查询操作

Posted 2023-05-16

java

参考技术A 我刚写了一个只有插入的，望采纳
import java.sql.*;
import java.util.*;
public class TestPre
public static void main(String[] args)
int i=0,deptno=0;//i只做while循环使用，deptno是表dept2中的一个属性，类型是int
String dname=null,loc=null;//dname和loc也是表dept2的属性，类型是String
Scanner s=new Scanner(System.in);
System.out.println("请输入3个参数");
while(i<3)
try
deptno=s.nextInt();
i++;
dname=s.next();
i++;
loc=s.next();
i++;
catch(InputMismatchException e)
System.out.println("输入的类型不符,退出");
System.exit(-1);


Connection conn=null;
PreparedStatement pstmt=null;
try
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost/mydata?"+ "user=root&password=root");
pstmt=conn.prepareStatement("insert into dept2 values(?,?,?)");
pstmt.setInt(1, deptno);
pstmt.setString(2, dname);
pstmt.setString(3, loc);
pstmt.executeUpdate();
System.out.println("插入完成");
catch (ClassNotFoundException e)
System.out.println("连接数据库不成功，程序退出");
System.exit(-1);
catch (SQLException e)
System.out.println("连接数据库不成功，程序退出");
System.exit(-1);

finally
try
if(pstmt!=null)
pstmt.close();
pstmt=null;

if(conn!=null)
conn.close();
conn=null;

catch(SQLException e)
e.printStackTrace();



参考技术B 增删改查。。是做程序最简单的东西。。。楼主还是自己动手啊。。。。 参考技术C 1.增加
String s1="insert into tableNames (id,name,password) values(myseq.nextval,?,?);"
Class.forName(driver);
Connection conn = DriverManager.getConnection(url,dbUser,dbPwd);
PreparedStatement prepStmt = conn.prepareStatement(s1);
prepStmt.setString(1,name);
prepStmt.setString(2,password);
ResultSet rs=stmt.executeUpdate();
2、删除
String s2="delete from tbNames where name=?";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url,dbUser,dbPwd);
PreparedStatement prepStmt = conn.prepareStatement(s2);
prepStmt.setString(1,name);
ResultSet rs=stmt.executeUpdate();
3、修改
String s3=“update tbNames set name=? where id=?”;
Class.forName(driver);
Connection conn = DriverManager.getConnection(url,dbUser,dbPwd);
PreparedStatement prepStmt = conn.prepareStatement(s3);
prepStmt.setString(1,name);
prepStmt.setString(2,id);
ResultSet rs=stmt.executeUpdate();
4、查询
String s4="select id,name,password from tbNames";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url,dbUser,dbPwd);
Statement stmt=conn.createStatement();
ResultSet rs = stmt.executeQuery(s4);
while(rs.next)
int id=rs.getInt(1);
String name = rs.getString(2);
String pwd=rs.getString(3);
System.out.println(id+name+pwd);

以上四步必须都得关闭连接；！！！
rs.close();
stmt.close();
conn.close(); 参考技术D 增删改查 这是最基本的。 劝楼主还是自己动手写写。

Java中的JDBC_part1

简介

JAVA程序想要对数据库进行访问，需要有JDBC驱动程序的支持。JDBC驱动程序提供了对各种主流数据库的接口，程序员只需要学习掌握这一套接口，就可以实现对所有数据库的访问代码编写。

一般步骤

1. JAVA访问数据库一般分为以下步骤
2. 加载JDBC驱动程序
3. 创建对数据库的连接
4. 执行SQL语句
5. 获取执行结果并对其处理
6. 关闭连接资源

示例代码:

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;     public class Hello {        static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";        static final String DB_URL = "jdbc:mysql://localhost:3306/mldn";        static final String USERNAME = "root";        static final String PASSWORD = "admin";            public static void main(String a[])      {        Connection conn = null;        Statement stmt = null;        ResultSet rs = null;        try               {               //加载驱动                      Class.forName(JDBC_DRIVER);                      //获取链接                      conn = DriverManager.getConnection(DB_URL, USERNAME, PASSWORD);                      //执行SQL语句                      stmt = conn.createStatement();                      rs = stmt.executeQuery("SELECT name FROM user;");                      //获取结果                      while(rs.next())                      {                            System.out.println("Hello " + rs.getString("name"));                      }               }        //异常处理        catch (ClassNotFoundException e)               {                      // TODO Auto-generated catch block                      e.printStackTrace();               } catch (SQLException e)               {                      // TODO Auto-generated catch block                      e.printStackTrace();               }        finally        {               //资源清理                      try                      {                            conn.close();                            stmt.close();                            rs.close();                      }                      catch(Exception e)                      {                            //ignore exceptions when closing.                      }               }            }  }