package packagename; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class classname { public static String url = "jdbc:mysql://localhost:3306/test";//characterEncoding=GBK public static String username = "root"; public static String password = "root"; public static Connection con; public static Statement stmt; public static ResultSet rs; public static PreparedStatement pstmt; public static void main(String[] args) throws SQLException { connect(); //select(); //insert(); //update(); //delete(); close(); } public static void connect() { // 定位驱动 try { Class.forName("com.mysql.jdbc.Driver"); System.out.println("加载驱动成功!"); } catch (ClassNotFoundException e) { System.out.println("加载驱动失败!"); e.printStackTrace(); } // 建立连接 try { con = DriverManager.getConnection(url, username, password); stmt = con.createStatement(); System.out.println("数据库连接成功!"); } catch(SQLException e) { System.out.println("数据库连接失败!"); e.printStackTrace(); } } public static void select() { try { String sql="select * from test where name=? "; pstmt=con.prepareStatement(sql); pstmt.setString(1,"root"); //String sql="select * from test where name=‘root‘ "; //rs = stmt.executeQuery(sql); rs=pstmt.executeQuery(); while (rs.next()) { System.out.println("你的第一个字段内容为:"+rs.getString("name")); System.out.println("你的第二个字段内容为:"+rs.getInt(1)); } rs.close(); }catch (Exception e) { System.out.println("数据查询失败!"); e.printStackTrace(); } } public static void insert() { try { String sql="insert into test (id,name) values(‘2‘,‘admin‘)"; stmt.executeUpdate(sql); System.out.println("数据插入成功!"); }catch (Exception e) { System.out.println("数据插入失败!"); e.printStackTrace(); } } public static void update() { try { String sql="update test set name=‘rootroot‘ where id=1"; stmt.executeUpdate(sql); System.out.println("数据更新成功!"); }catch (Exception e) { System.out.println("数据更新失败!"); e.printStackTrace(); } } public static void delete() { try { String sql="delete from test where id=?"; pstmt = con.prepareStatement(sql); pstmt.setInt(1,1); pstmt.executeUpdate(); System.out.println("数据删除成功!"); }catch (Exception e) { System.out.println("数据删除失败!"); e.printStackTrace(); } } public static void close() { try{ if(rs!=null) rs.close(); if(stmt!=null) stmt.close(); if(con!=null) con.close(); }catch(Exception e) { e.printStackTrace(); } } }
时间: 2024-10-10 14:50:29