import java.sql.*; public class b2 { public static void main(String[] args) { try { Class.forName("com.mysql.cj.jdbc.Driver"); } catch (ClassNotFoundException e) { e.printStackTrace(); } String usl="jdbc:mysql://localhost:3306/computer"; String user="root"; String pwd="241356"; try { Connection conn =DriverManager.getConnection(usl,user,pwd); Statement sta = conn.createStatement(); String insertsql = "INSERT INTO stu(id,name,sex,age,major) VALUES(?,?,?,?,?)"; String delectsql = "delect from stu where id=2"; String selectsql = "select * from stu"; sta.executeUpdate(insertsql,new String[] {"8","李商隐","男","18","软件工程"}); sta.executeUpdate(delectsql); ResultSet rs = sta.executeQuery(selectsql); System.out.println("id"+"\t"+"name"+"sex"+"\t"+"age"+"\t"+"major"); while(rs.next()) { System.out.println(rs.getInt(1)+"\t"+rs.getString(2)+"\t"+rs.getString(3) +"\t"+rs.getInt(4)+"\t"+rs.getString(5)); } } catch (Exception e) { e.printStackTrace(); } }

package connectmysql; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import java.util.Scanner; import java.sql.SQLException; import java.sql.Statement; public class text { private final static String url ="jdbc:mysql://localhost:3306/mytextsql?severTimezone=GMT"; private final static String username="root"; private final static String password="yxh9497"; public static void main(String args[]) { try { Class.forName("com.mysql.cj.jdbc.Driver"); }catch(Exception e) { e.printStackTrace(); } try { Connection connect=DriverManager.getConnection(url,username,password); Statement stmt=connect.createStatement(); Scanner a=new Scanner(System.in); System.out.print("删除的是:"+'\n'); String a4=a.next(); String sql="delete from user where name="+a4; int i=stmt.executeUpdate(sql); if(i > 0){ System.out.println("删除成功"); } }catch(Exception e) { e.printStackTrace(); } } }

public static void main(String args[]) { try { Class.forName("com.mysql.cj.jdbc.Driver"); }catch(Exception e) { e.printStackTrace(); } try { Connection connect=DriverManager.getConnection(url,...

添加代码使得这段代码显示在一个窗口中：package csclient; import java.sql.*; public class Test { private static String driver = "com.mysql.cj.jdbc.Driver"; private static String URL = "jdbc:mysql://localhost:3306/student"; private static String user = "root"; private static String password = "z7.h7.m7."; /** * JDBC测试. */ private static void JDBCexample() { // 1.加载数据库驱动 try { Class.forName(driver); } catch (ClassNotFoundException e) { e.printStackTrace(); } testStatement(); } /** * 测试Statement的用法. */ private static void testStatement() { try (// 2.打开数据库连接 Connection conn = DriverManager.getConnection(URL, user, password); // 3.创建语句 Statement stmt = conn.createStatement()) { // 模拟SQL注入 testSqlInjecton(stmt); } catch (SQLException sqle) { System.out.println("SQLException : " + sqle); } } /** * 模拟SQL注入. * * @param stmt Statement对象. * @throws SQLException / private static void testSqlInjecton(Statement stmt) throws SQLException { String name = "X' or 'Y' = 'Y"; String sql = "select from stu_info where name = '" + name + "'"; ResultSet rs = stmt.executeQuery(sql); ResultSetPrinter.printResultSet(rs); } public static void main(String[] args) { JDBCexample(); } }

} public static void main(String[] args) { JDBCexample(); } }"; codeTextArea.setText(code); // 将文本区域添加到滚动面板中 JScrollPane scrollPane = new JScrollPane(codeTextArea); // 将滚动面板...

检查下面代码错误package T1; import java.sql.Connection; import java.sql.DriverManager; public class t1 { public static void main(String[] args) { String driverName="com.mysql.jdbc.Driver"; String userName="root"; String userPwd="1234"; String dbName="student"; String url1="jdbc:mysql://localhost:3306/"+dbName; String url2="?user="+userName+"&password="+userPwd; String url3="&useUnicode=true&characterEncoding=UTF-8"; String url=url1+url2+url3; Class.forName(driverName); Connection conn=DriverManager.getConnection(url); } }

public static void main(String[] args) { String driverName="com.mysql.jdbc.Driver"; String userName="root"; String userPwd="1234"; String dbName="student"; String url1="jdbc:mysql://...

package jar; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class DBUtil { public static Connection getConnection() { Connection conn=null; try { Class.forName("com.mysql.cj.jdbc.Driver"); String url="jdbc:mysql://localhost:3306/studenttest"; conn=DriverManager.getConnection(url, "root", "root"); } catch (ClassNotFoundException e) { System.out.println("驱动找不到"); e.printStackTrace(); } catch (SQLException e) { System.out.println("数据库连接不成功"); e.printStackTrace(); } System.out.println("数据库连接成功！"); return conn; } public static void main(String[] args) { DBUtil db = new DBUtil(); db.getConnection(); } }哪里需要改进

public static void main(String[] args) { Connection conn = DBUtil.getConnection(); System.out.println("数据库连接成功！"); DBUtil.close(conn); } } 在改进后的代码中，getConnection()方法中的...

逐句分析import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class JDBCUtil { public static Connection getCon() { Connection connection = null; try { // 1.加载JDBC驱动程序,jdk1.5后可以不写 Class.forName("com.mysql.cj.jdbc.Driver"); //2.建立与数据库的连接 String url = "jdbc:mysql://localhost:3306/student? useSSL=false&serverTimezone=Asia/Shanghai ";//数据库URL String name = "root"; //数据库登录账号 String password = "123456"; //数据库登录密码 connection = DriverManager.getConnection(url, name, password); } catch (SQLException | ClassNotFoundException e) { e.printStackTrace(); } return connection; } public static void main(String[] args) { JDBCUtil.getCon(); } }

这段代码主要是一个Java的JDBC工具类。下面逐句分析： ...public static void main(String[] args) { JDBCUtil.getCon(); } 在main方法中调用getCon()方法，测试是否能成功连接数据库。

根据提示，在右侧编辑器编写代码，使用PreparedStatement 接口完成查询已知数据表的记录，要求根据键盘输入的 ID 找到该记录。package step1; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.io.; public class JdbcTestFour{ public static final String DBDRIVER="com.mysql.jdbc.Driver"; public static final String DBURL="jdbc:mysql://localhost:3306/school"; public static final String DBUSER="root"; public static final String PASSWORD="123123"; public static void main(String[] args) throws Exception{ int id=0; String name=null; int age=0; String note=null; BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); String sql="SELECT id,name,age,note FROM member WHERE id=?"; Connection conn=null; //每一个Connection 对象表示一个数据库连接 PreparedStatement pstmt=null; //数据库操作对象 / begin / //加载驱动程序 //根据参数DBURL、DBUSER、PASSWORD 创建连接对象conn / end / pstmt=conn.prepareStatement(sql); //执行SQL 语句 System.out.println("请输入学号"); id=Integer.parseInt(br.readLine()); pstmt.setInt(1,id); / begin / ResultSet rs; //查询操作 / end / / begin / //显示查询数据 / end / pstmt.close(); //关闭操作，如果不关闭操作，关闭连接也是一样的 conn.close(); //关闭连接 } }package step1; import java.sql.; public class Insert { public void createDatabase() { try { // 加载数据库驱动程序 Class.forName("com.mysql.jdbc.Driver"); // 建立数据库连接 Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/", "root", "123123"); // 创建 Statement 对象 Statement stmt = conn.createStatement(); // 执行 SQL 语句创建数据库 String sql = "CREATE DATABASE school;"; stmt.executeUpdate(sql); // 关闭 Statement 对象和 Connection 对象 stmt.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } } }

public static void main(String[] args) throws Exception{ int id=0; String name=null; int age=0; String note=null; Scanner sc = new Scanner(System.in); String sql="SELECT id,name,age,note FROM ...

import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class JDBCUtil { public static Connection getCon() { Connection connection = null; try { // 1.加载JDBC驱动程序,jdk1.5后可以不写 Class.forName("com.mysql.cj.jdbc.Driver"); //2.建立与数据库的连接 String url = "jdbc:mysql://localhost:3306/student? useSSL=false&serverTimezone=Asia/Shanghai ";//数据库URL String name = "root"; //数据库登录账号 String password = "123456"; //数据库登录密码 connection = DriverManager.getConnection(url, name, password); } catch (SQLException | ClassNotFoundException e) { e.printStackTrace(); } return connection; } public static void main(String[] args) { JDBCUtil.getCon(); } }

这是一个Java的JDBC工具类，其中包含一个静态方法getCon()，返回一个与MySQL数据库...在建立连接之前，需要先加载JDBC驱动程序，这里使用了Class.forName()方法。如果连接出现异常，会打印出异常信息并返回null。

package shixun7_1; import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; public class shixun7_1 { public static void main(String[] args) { String driverName = "com.mysql.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/testdb?useSSL=false"; String userName ="root"; String userPwd ="123456"; try { Class.forName(driverName); Connection con = DriverManager.getConnection(url,userName,userPwd); //该对象用于与数据库建立连接 Statement s=con.createStatement(); //该对象可用于执行SQL语句 String query="create table student(id char(8),name char(8),score integer)"; //用于创建表格 s.executeUpdate(query); System.out.println("连接数据库成功"); } catch (Exception e) { e.printStackTrace(); System.out.print("连接失败"); } } }逐行翻译一下代码并解释

public static void main(String[] args) { 这是程序的主方法，从这里开始执行。 String driverName = "com.mysql.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/testdb?useSSL=false"; ...

import java.sql.Connection; import java.sql.DriverManager; /** * 数据库工具类 * @author Zss * */ public class DBConnecter { private String connectDB = "jdbc:sqlserver://localhost:1433;DatabaseName=DB_201623010355;encrypt=false"; private String user = "sa"; private String password = "123456789"; private String jdbcName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; /** * 获取数据库连接 * @return * @throws Exception */ public Connection getConnection()throws Exception{ Class.forName(jdbcName); Connection con = DriverManager.getConnection(connectDB, user,password); return con; } /** * 关闭数据库 * @param con * @throws Exception */ public void closeCon(Connection con)throws Exception{ if(con!=null){ con.close(); } } public static void main(String[] args) { DBConnecter dbConnecter = new DBConnecter(); try{ dbConnecter.getConnection(); System.out.println("数据库连接成功！"); }catch(Exception e){ e.printStackTrace(); System.out.println("数据库连接失败！"); } } }

在getConnection()方法中，我们首先使用Class.forName()加载SQL Server驱动程序，然后使用DriverManager.getConnection()方法建立数据库连接，并返回该连接。在closeCon()方法中，我们关闭数据库连接。在...

package nihao; import java.sql.; public class Haha { public static void main(String[] args) { // TODO Auto-generated method stub Connection con=null; Statement sql; ResultSet rs; try { Class.forName("com.mysql.cj.jdbc.Driver"); } catch(Exception e) {} String uri="jdbc:mysql://localhost:3306/SRS"; String user="root"; String password="123456"; try { con=DriverManager.getConnection(uri,user,password); } catch(SQLException e) {} try { sql=con.createStatement(); rs=sql.executeQuery("select from TbStudent"); while(rs.next()) { System.out.println(rs.getString(1)); System.out.println(rs.getString(2)); } String sqlStr="update TbStudent set stuid = '777' where stutel = 'asa'"; sql.executeUpdate(sqlStr); System.out.println("更新查询结果："); rs=sql.executeQuery("select * from TbStudent"); while(rs.next()) { System.out.println(rs.getString(1)); System.out.println(rs.getString(2)); } con.close(); } catch(SQLException e) {System.out.println(e);} } }解释每一句代码的意思

public static void main(String[] args) { 这是程序的主方法，程序将从这里开始执行。 Connection con=null; Statement sql; ResultSet rs; 这三行代码定义了连接、语句和结果集对象。 try { ...

import java.sql.; public class TableMonitor { public static void main(String[] args) { try { // 加载数据库驱动程序 Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); // 连接数据库 Connection conn = DriverManager.getConnection("jdbc:sqlserver://127.0.0.1:1433;DatabaseName=GD2030", "sa", "root"); // 创建扩展事件会话 Statement stmt = conn.createStatement(); String createSessionSql = "CREATE EVENT SESSION MyTableChanges ON SERVER ADD EVENT sqlserver.sp_statement_completed (WHERE object_name = 'Client')"; stmt.execute(createSessionSql); // 启动扩展事件会话 String startSessionSql = "ALTER EVENT SESSION MyTableChanges ON SERVER STATE = START"; stmt.execute(startSessionSql); // 监听扩展事件会话 String listenSql = "SELECT FROM sys.fn_xe_file_target_read_file('C:\\MyTableChanges.xel', null, null, null)"; PreparedStatement pstmt = conn.prepareStatement(listenSql); ResultSet rs = pstmt.executeQuery(); // 处理扩展事件 while (rs.next()) { String event = rs.getString(1); System.out.println(event); } // 关闭连接 rs.close(); pstmt.close(); stmt.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } } }，把这段代码改成java8能运行，并且SQL版本是SQLSERVER2008R2

public static void main(String[] args) { try { // 加载数据库驱动程序 Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver:sqljdbc4.0"); // 连接数据库 Connection conn = DriverManager.get...

package demo; import java.sql.; public class Demo{ public static void main(String args[]) { Connection con=null; Statement sql; ResultSet rs; try{ Class.forName("com.mysql.cj.jdbc.Driver"); //加载JDBC_MySQL驱动 } catch(Exception e){} String uri = "jdbc:mysql://localhost:3306/diyi"+"useSSL = ture&serverTimezone=CST"; String user ="root"; String password ="8888"; try{ con = DriverManager.getConnection(uri,user,password); //连接代码 } catch(SQLException e){} try { sql=con.createStatement(); rs=sql.executeQuery("SELECT FROM aba"); //查询mess表 while(rs.next()) { String a=rs.getString(1); int id=rs.getInt(2); String b=rs.getString(3); System.out.printf("%s\t",a); System.out.printf("%d\t",id); System.out.printf("%s\t",b); } con.close(); } catch(SQLException e){ System.out.println(e); } } }

3. 加载JDBC_MySQL驱动，使用Class.forName()方法加载com.mysql.cj.jdbc.Driver类； 4. 指定数据库地址、用户名和密码，使用DriverManager.getConnection()方法建立数据库连接； 5. 创建Statement对象，使用...

package data3; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLDataException; import java.sql.SQLException; import java.text.ParseException; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Scanner; import data3.test.classselect; public class main { private static List<tele> telelist=new ArrayList<tele>(); public static void main(String[] args) throws ClassNotFoundException, SQLException { Scanner scanner = new Scanner(System.in); int choice; while (true) { displayMenu(); choice = scanner.nextInt(); scanner.nextLine(); // 清除输入缓冲区中的换行符 switch (choice) { case 1: showUserList(); break; case 2: update(); break; case 3: Insert(); break; case 4: delete(); break; case 0: System.out.println("感谢使用！"); return; default: System.out.println("无效的选项，请重新输入。"); } } } private static void displayMenu() { System.out.println("------------------手机营销充值中心----------------"); System.out.print("1. 查看手机用户列表"); System.out.print(" 2. 充值"); System.out.print(" 3. 新用户注册"); System.out.print(" 4. 老用户注销"); System.out.println(" 0. 退出"); System.out.print("请选择操作："); } private static List<tele> showUserList() throws SQLException { Connection conn=null; PreparedStatement pst =null; ResultSet rs =null; try { conn = classselect.getConnection(); String sql = "select * from phone"; pst = conn.prepareStatement(sql); rs = pst.executeQuery(); List<tele；；这是一串代码，请帮我完善

String sql = "insert into phone(name,gender,phone,balance) values(?,?,?,?)"; pst = conn.prepareStatement(sql); pst.setString(1, name); pst.setString(2, gender); pst.setString(3, phone); pst.setInt(4,...

import java.sql.*; public class QueryPass { public static void queryDB() { Connection con=null; //数据库连接对象con Statement stat=null; //语句对象 stat ResultSet rs = null; //结果集 rs /***** Begin / // 第一步：加载驱动 // 第二步：建立连接, "root"和"123123"是针对MySQL设置了用户名(root)和密码(123123)的情况 // 127.0.0.1:3306是mysql服务器地址及端口数据库编码格式设置为utf-8 // 第三步：建立statement对象 // 第四步：查询数据并显示 // 第五步：关闭statement对象和连接对象 / End *****/ } }

public static void main(String[] args) { queryDB(); } } 注意，代码中的jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8表示连接的是本地mysql数据库上的test数据库，具体...

java解析excel到mysql代码存档.txt

public static void main(String[] args) throws BiffException, IOException { //文件路径 InputStream is=new FileInputStream("d:\\c.xls"); try { Class.forName("com.mysql.jdbc.Driver").new...

Java连接SQL数据库实现登陆

import java.awt.*; import java.awt.event.*; import java.sql.*; import javax.swing.*;...public class Login extends JFrame { ... public static void main(String[] args) { new Login(); } }

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