数据库连接案例.docx

Ex4.8(数据库连接)import java.sql.Connection;import java.sql.DriverManager;public class ConnectionTestpublic static void main(String args )throws Exception Class.forName(com.mysql.jdbc.Driver); /加载数据库驱动 String url=jdbc:mysql:/localhost:3306/xsgl; Connection con=DriverManager.getConnection(url,root,1234);EX:P254（登陆界面-1）import java. sql. * ;public class DBConnectionConnection con=null; /数据库连接对象public DBConnection( )tryClass.forName(com.mysql.jdbc.Driver); /加载数据库驱动con=DriverManager.getConnection(jdbc:mysql:/localhost:3306/xsgl,root,1234);catch(Exception e)System.out.print(数据库访问失败+e.getMessage( );EX:P255（登陆界面-2）import java.awt.event. * ;import java.awt. * ;import java.sql.Connection;import java.sql.ResultSet;import java.sql.Statement;import javax.swing. * ;public class Login implements ActionListenerJFrame f;JLabel l1;JLabel l2;JTextField jt1;JTextField jt2;JButton an1;JButton an2;public Login()f=new JFrame();f.setTitle(学生登陆);f.setLayout(new FlowLayout() );f.setLocation(400,300);l1=new JLabel(请输入学号:);l2=new JLabel(请输入姓名:);jt1=new JTextField(15);jt2=new JTextField(15);an1=new JButton(登陆);an2=new JButton(取消);an1.addActionListener(this);f.add(l1);f.add(jt1);f.add(l2);f.add(jt2);f.add(an1);f.add(an2);f.setSize(300,200);f.setResizable(false);f.setVisible(true);public static void main(String args )new Login();public void actionPerformed(ActionEvent e)String xuehao=jt1.getText( );String xingming=jt2.getText( );DBConnection db=new DBConnection( );Connection conn=db.con;tryStatement stmt= conn.createStatement( );ResultSet rs=stmt.executeQuery(select*from student where stuno= +xuehao+and name=+xingming+);if(rs.next() ) JOptionPane.showConfirmDialog(null,登陆成功!,提示信息,JOptionPane.DEFAULT_OPTION,JOptionPane.INFORMATION_MESSAGE);elseJOptionPane.showConfirmDialog(null,登陆失败!,提示信息,JOptionPane.DEFAULT_OPTION,JOptionPane.INFORMATION_MESSAGE);catch(Exception el) System.out.print(查询不成功+el.getMessage( ) );Ex4.10（插入操作）import java. sql.Connection;import java. sql.DriverManager;import java. sql.Statement;public class DataInsertTestpublic static void main(String args )throws ExceptionClass.forName(com.mysql.jdbc.Driver);String url=jdbc:mysql:/localhost:3306/xsgl;Connection con=DriverManager.getConnection(url,root,1234);Statement st=con.createStatement( );String sql=insert into student(stuno,name)values(lnjd12303,angle);st.executeUpdate(sql);st.close( );con.close( ); Ex4.11（插入操作-Statement类）import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;public class DataInsertTestpublic static void main(String args )throws ExceptionString stuno=;String name=;Class.forName(com.mysql.jdbc.Driver);String url=jdbc:mysql:/localhost:3306/xsgl;Connection con=DriverManager.getConnection(url,root,1234);Statement st=con.createStatement( );String sql=insert into student(stuno,name)values(+stuno+,+name+);st.executeUpdate(sql);st.close( );con.close( );Ex4.13（删除操作）import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;public class DataDeleteTestpublic static void main(String args )throws ExceptionClass.forName(com.mysql.jdbc.Driver);String url=jdbc:mysql:/localhost:3306/xsgl;Connection con=DriverManager.getConnection(url,root,1234);Statement st=con.createStatement( );String sql=delete from student where stuno=lnjd12303;st.executeUpdate(sql);st.close( );con.close( );Ex4.14（修改操作）import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;public class DataUpdateTestpublic static void main(String args )throws ExceptionClass.forName(com.mysql.jdbc.Driver);String url=jdbc:mysql:/localhost:3306/xsgl;Connection