Java+SQL server 学生宿舍管理系统 数据库课程设计 简单控制台输出功能 增删查改统计

package room_system; import java.security.PublicKey; import java.sql.*; public class JDBCUnit { /* 驱动，定义连接数据库类型：SQL SERVER2012*/ private static String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";//驱动:com.microsoft.sqlserver.jdbc.SQLServerDriver public static String SerName; //服务器名字:127.0.0.1 public static String Dbname; //数据库名:room_system public static String userName; //用户名:sa public static String userPwd; //密码:123456 public static Connection getConnection(){ String dbURL="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=room_system"; Connection conn = null; try { //1.注册驱动 Class.forName(driverName); //2.建立连接 conn = DriverManager.getConnection(dbURL, "sa", "123456"); } catch (Exception e) { e.printStackTrace(); } return conn; } /** * 使用statement对象执行DML语句 */ public static void stmt_DML(String sql) { Connection conn = null; Statement stmt = null; try { conn = getConnection(); //1.创建Statement对象 stmt = conn.createStatement(); //2.执行sql语句 stmt.execute(sql); //3.关闭资源 stmt.close(); //关闭数据执行结果集合 conn.close(); //关闭数据库连接 } catch (Exception e) { e.printStackTrace(); } } /** * 使用PreparedStatement执行SQL语句 */ public static void ps_DML(String sql,ResultSet rs) { try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); //4.操作结果集 rs=ps.executeQuery(); //5.关闭资源 ps.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } /** * 判断登录用户是否存在 */ public static boolean login_flag(String usrName,String usrPwd) { String sql= "select * from LgTbl where usrName="+"'"+usrName+"'"+" and usrPwd= "+"'"+usrPwd+"'"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } /** * 判断查询输入学号Sno结果是否为空 */ public static boolean select_flag(String Sno) { String sql= "select Sno from Student where Sno=ltrim(rtrim("+"'"+Sno+"'))"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } /** * 判断查询输入楼栋结果是否为空 */ public static boolean select_Bno(String Bno) { String sql= "select Bno from Room where Bno=ltrim(rtrim("+"'"+Bno+"'))"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } /** * 判断查询输入宿舍结果是否为空 */ public static boolean select_Rno(String Rno) { String sql= "select Rno from Room where Rno=ltrim(rtrim("+"'"+Rno+"'))"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } /** * 判断查询输入维修楼栋结果是否为空 */ public static boolean select_weixiuBno(String Bno) { String sql= "select Bno from Repair where Bno=ltrim(rtrim("+"'"+Bno+"'))"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } /** * 判断查询输入维修宿舍结果是否为空 */ public static boolean select_weixiuRno(String Rno) { String sql= "select Rno from Repair where Rno=ltrim(rtrim("+"'"+Rno+"'))"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } /** * 判断查询输入物品编号结果是否为空 */ public static boolean select_Pno(String Pno) { String sql= "select Pno from Goods where Pno=ltrim(rtrim("+"'"+Pno+"'))"; boolean flag=false; try { Connection conn = getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()) { flag = true; } else { flag = false; } rs.close(); ps.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return flag; } }