数据库连接-登录
1 public class Demo3 { 2 public static void main(String[] args) throws SQLException, ClassNotFoundException { 3 //1.注册驱动 4 Class.forName("com.mysql.jdbc.Driver"); 5 //2.获取连接对象 6 String url="jdbc:mysql://localhost:3306/day22_JDBC?characterEncoding=UTF-8"; 7 String username="root"; 8 String password="123456"; 9 Connection conn=DriverManager 10 .getConnection(url,username,password); 11 //3.获取语句执行对象 12 Statement sta=conn.createStatement(); 13 //让用户输入用户名和密码 14 Scanner sc=new Scanner(System.in); 15 System.out.println("请输入用户名"); 16 String uname=sc.next(); 17 System.out.println("请输入密码"); 18 String pwd=sc.next(); 19 20 //4.执行sql 21 //用户信息写死 22 String sql="SELECT COUNT(*) FROM USER WHERE uname='"+uname+"' AND pwd='"+pwd+"'"; 23 // 24 // 25 ResultSet rs=sta.executeQuery(sql); 26 //5.处理结果集 27 // 28 int count=0; 29 while(rs.next()){ 30 count=rs.getInt(1); 31 } 32 if(count>0){ 33 System.out.println("登陆成功~"); 34 } 35 else{ 36 System.out.println("登陆失败~"); 37 38 } 39 //6.释放资源 40 rs.close(); 41 sta.close(); 42 conn.close(); 43 } 44 }
public class Demo3 {public static void main(String[] args) throws SQLException, ClassNotFoundException {//1.注册驱动Class.forName("com.mysql.jdbc.Driver");//2.获取连接对象String url="jdbc:mysql://localhost:3306/day22_JDBC?characterEncoding=UTF-8";String username="root";String password="123456";Connection conn=DriverManager.getConnection(url,username,password);//3.获取语句执行对象Statement sta=conn.createStatement();//让用户输入用户名和密码Scanner sc=new Scanner(System.in);System.out.println("请输入用户名");String uname=sc.next();System.out.println("请输入密码");String pwd=sc.next();//4.执行sql//用户信息写死String sql="SELECT COUNT(*) FROM USER WHERE uname='"+uname+"' AND pwd='"+pwd+"'";////ResultSet rs=sta.executeQuery(sql);//5.处理结果集//int count=0;while(rs.next()){count=rs.getInt(1);}if(count>0){System.out.println("登陆成功~");}else{System.out.println("登陆失败~");}//6.释放资源rs.close();sta.close();conn.close();}}