标签：uniq git import lse ring ble 增删查改 问题 日期
根据到目前为止已经复习了的基础知识，在git上找了个小程序写着玩玩，下面记录过程。
建表我使用的是MySQL数据库，用的是navicat软件，ER图照搬git上的，由于作者使用的是Oracle建表，所以数据类型有些出入，问题不大。
商品表
CREATE TABLE `goods` ( `GID` int(10) NOT NULL COMMENT ‘商品编号，自动生成‘, `GNAME` varchar(20) NOT NULL COMMENT ‘商品名称，唯一约束‘, `GPRICE` decimal(18,1) NOT NULL COMMENT ‘商品价格‘, `GNUM` int(11) NOT NULL COMMENT ‘商品数量‘, PRIMARY KEY (`GID`), UNIQUE KEY `GNAME` (`GNAME`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
销售员表
CREATE TABLE `salesman` ( `SID` int(10) NOT NULL COMMENT ‘营业员编号，自动生成‘, `SPASSWORD` varchar(20) NOT NULL COMMENT ‘营业员密码‘, `SNAME` varchar(10) NOT NULL COMMENT ‘营业员姓名，用于登录收银，唯一约束‘, PRIMARY KEY (`SID`), UNIQUE KEY `SNAME` (`SNAME`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
商品销售表
CREATE TABLE `gsales` ( `GSID` int(10) NOT NULL COMMENT ‘销售编号，自动生成‘, `GID` int(10) NOT NULL COMMENT ‘商品编号‘, `SID` int(10) NOT NULL COMMENT ‘营业员编号‘, `SDATE` datetime NOT NULL COMMENT ‘销售日期‘, `SNUM` int(11) NOT NULL COMMENT ‘销售数量‘, PRIMARY KEY (`GSID`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
一、主体结构如下：
dao：处理数据功能
db:数据库相关
entity:模型相关
page:页面相关
tools:需要用到的工具类
二、
1.我的思路是，从简单到复杂开始写，首先根据已经建好的数据库表编写实体类。
Goods.java
package entity; public class Goods { //商品编号，自动生成 private int gid; //商品名称 private String gname; //商品价格 private double gprice; //商品数量 private int gnum; public Goods(int gid, String gname, double gprice, int gnum) { this.gid = gid; this.gname = gname; this.gprice = gprice; this.gnum = gnum; } public Goods(String gname, double gprice, int gnum) { this.gname = gname; this.gprice = gprice; this.gnum = gnum; } /* * 根据编号更改商品数量 */ public Goods(int gid,int gnum) { this.gid = gid; this.gnum = gnum; } /* * 根据编号更改商品价格 */ public Goods(int gid,double gprice) { this.gid = gid; this.gprice = gprice; } /* * 根据商品编号更改商品名称 */ public Goods(int gid, String gname) { this.gid = gid; this.gname = gname; } //getter，setter方法 public int getGid() { return gid; } public void setGid(int gid) { this.gid = gid; } public String getGname() { return gname; } public void setGname(String gname) { this.gname = gname; } public double getGprice() { return gprice; } public void setGprice(double gprice) { this.gprice = gprice; } public int getGnum() { return gnum; } public void setGnum(int gnum) { this.gnum = gnum; } }
SalesMan.java
1 package entity; 2 3 public class SalesMan { 4 //营业员编号 5 private int sid; 6 //营业员密码 7 private String spassword; 8 //营业员姓名 9 private String sname; 10 11 /* 12 * 根据sid设置密码 13 */ 14 public SalesMan(int sid, String spassword) { 15 this.sid = sid; 16 this.spassword = spassword; 17 } 18 19 /* 20 * 根据sid设置姓名 21 */ 22 public SalesMan (int sid,String sname,String spassword) { 23 this.sid = sid; 24 this.sname = sname; 25 this.spassword = spassword; 26 } 27 28 public SalesMan(String spassword, String sname) { 29 this.sid = sid; 30 this.spassword = spassword; 31 this.sname = sname; 32 } 33 34 //getter,setter方法 35 public int getSid() { 36 return sid; 37 } 38 39 public void setSid(int sid) { 40 this.sid = sid; 41 } 42 43 public String getSpassword() { 44 return spassword; 45 } 46 47 public void setSpassword(String spassword) { 48 this.spassword = spassword; 49 } 50 51 public String getSname() { 52 return sname; 53 } 54 55 public void setSname(String sname) { 56 this.sname = sname; 57 } 58 }
Gsales.java
1 package entity; 2 3 import java.util.Date; 4 5 public class Gsales { 6 7 //商品编号 8 private int gid; 9 //销售员编号 10 private int sid; 11 //销售数量 12 private int snum; 13 14 15 private String gname; 16 private double gprice; 17 private int gnum; 18 private int allSnum; //单种商品销量总和 19 20 public Gsales(int gid, int sid, int snum) { 21 this.gid = gid; 22 this.sid = sid; 23 this.snum = snum; 24 } 25 26 public Gsales(String gname,double gprice,int gnum,int allSnum) { 27 this.gname = gname; 28 this.gprice = gprice; 29 this.gnum = gnum; 30 this.allSnum = allSnum; 31 } 32 33 //setter,getter方法 34 public int getGid() { 35 return gid; 36 } 37 38 public void setGid(int gid) { 39 this.gid = gid; 40 } 41 42 public int getSid() { 43 return sid; 44 } 45 46 public void setSid(int sid) { 47 this.sid = sid; 48 } 49 50 public int getSnum() { 51 return snum; 52 } 53 54 public void setSnum(int snum) { 55 this.snum = snum; 56 } 57 58 public String getGname() { 59 return gname; 60 } 61 62 public void setGname(String gname) { 63 this.gname = gname; 64 } 65 66 public double getGprice() { 67 return gprice; 68 } 69 70 public void setGprice(double gprice) { 71 this.gprice = gprice; 72 } 73 74 public int getGnum() { 75 return gnum; 76 } 77 78 public void setGnum(int gnum) { 79 this.gnum = gnum; 80 } 81 82 public int getAllSnum() { 83 return allSnum; 84 } 85 86 public void setAllSnum(int allSnum) { 87 this.allSnum = allSnum; 88 } 89 }
2.编写主界面
主界面示意图：
主界面展示方法
1 private static void mainPage() { 2 System.out.println("*************************************\n"); 3 System.out.println("\t\t\t 1.商品维护"); 4 System.out.println("\t\t\t 2.前台收银"); 5 System.out.println("\t\t\t 3.商品管理"); 6 System.out.println("\n*************************************\n"); 7 8 System.out.println("\n请选择，输入选项或者按0退出:"); 9 while (true) { 10 String choice = ScannerChoice.ScannerInfo(); 11 String regex = "[0-3]";//正则表达式 12 if(choice.matches(regex)) { 13 int info = Integer.parseInt(choice); 14 switch (info) { 15 case 0: 16 System.out.println("----------------------------"); 17 System.out.println("您已退出系统！"); 18 System.exit(-1);//退出程序，返回值随便设置 19 break; 20 case 1: 21 System.out.println("正在进入商品维护页面..."); 22 break; 23 case 2: 24 System.out.println("正在进入前台收银页面..."); 25 break; 26 case 3: 27 System.out.println("正在进入商品管理页面..."); 28 break; 29 default: 30 break; 31 } 32 } 33 else { 34 System.err.println("输入有误!"); 35 System.out.print("重新选择或按0退出."); 36 } 37 } 38 }
之后会将这个方法完善，把打印语句改成对应的方法，进入到下个界面。
接下来编写商品维护界面的方法。
1 public static void maintaincePage() { 2 System.out.println("商场购物管理系统>>商品维护"); 3 System.out.println("*************************************\n"); 4 System.out.println("\t\t\t 1.添加商品\n"); 5 System.out.println("\t\t\t 2.更改商品\n"); 6 System.out.println("\t\t\t 3.删除商品\n"); 7 System.out.println("\t\t\t 4.显示所有商品\n"); 8 System.out.println("\t\t\t 5.查询商品\n"); 9 System.out.println("*************************************\n"); 10 System.out.println("请选择，输入数字或者按0返回上一级菜单"); 11 while(true) { 12 String choice = ScannerChoice.ScannerInfo(); 13 String regex = "[0-5]";//正则表达式 14 if (choice.matches(regex)) { 15 int info = Integer.parseInt(choice); 16 switch (info) { 17 case 0: 18 mainPage(); 19 break; 20 case 1: 21 System.out.println("开始添加商品..."); 22 break; 23 case 2: 24 System.out.println("开始更改商品..."); 25 break; 26 case 3: 27 System.out.println("开始删除商品..."); 28 break; 29 case 4: 30 System.out.println("开始显示商品..."); 31 break; 32 case 5: 33 System.out.println("开始查询商品..."); 34 break; 35 default: 36 break; 37 } 38 } else { 39 System.err.println("输入有误!"); 40 System.out.print("重新选择或按0回到上一级菜单."); 41 } 42 } 43 44 }
写maintaincePage()方法跟写mainPage()方法的思路类似，switch()中的方法暂时使用打印语句代替，接下来逐渐完善这些具体的方法，会涉及到数据库的增删查改。
为了降低程序的耦合性，将与商品增删查改有关的操作在GoodsPage类中实现。
1 package page; 2 3 import dao.GoodsDao; 4 import entity.Goods; 5 import tools.ScannerChoice; 6 7 /** 8 * 操作商品界面 9 */ 10 public class GoodsPage { 11 /** 12 * 添加商品界面 13 */ 14 public static void addGoodsPage() { 15 System.out.println("\t正在执行添加商品操作\n"); 16 System.out.println("\n请输入要添加商品的名称"); 17 String goodsName = ScannerChoice.ScannerInfo(); 18 19 System.out.println("\n请输入要添加商品的价格"); 20 double goodsPrice = Double.parseDouble(ScannerChoice.ScannerInfo()); 21 22 System.out.println("\n请输入要添加的商品的数量"); 23 int goodsNumber = Integer.parseInt(ScannerChoice.ScannerInfo()); 24 25 Goods goods = new Goods(goodsName,goodsPrice,goodsNumber); 26 boolean flag = new GoodsDao().addGoods(goods); 27 28 if(flag) { 29 System.out.println("\n\t您已经成功添加商品到数据库!"); 30 } else { 31 System.out.println("添加失败!"); 32 } 33 } 34 }
GoodsDao类是涉及商品类数据库操作的类。
1 package dao; 2 3 import entity.Goods; 4 import tools.DBtool; 5 6 import java.sql.Connection; 7 import java.sql.PreparedStatement; 8 import java.sql.SQLException; 9 10 public class GoodsDao { 11 public static boolean addGoods(Goods goods) { 12 Connection conn = DBtool.getConn(); 13 String sql = "insert into GOODS(GNAME,GPRICE,GNUM,GID) values(?,?,?,?)"; 14 PreparedStatement ptsmt = null; 15 try { 16 ptsmt = conn.prepareStatement(sql); 17 ptsmt.setString(1,goods.getGname()); 18 ptsmt.setString(2,goods.getGprice()+""); 19 ptsmt.setString(3,goods.getGnum()+""); 20 ptsmt.setString(4,goods.getGid()); 21 22 int rs = ptsmt.executeUpdate(); 23 if(rs > 0) { 24 return true; 25 } else 26 return false; 27 28 } catch (SQLException e) { 29 e.printStackTrace(); 30 } finally { 31 DBtool.close(conn,ptsmt); 32 } 33 return true; 34 } 35 }
DBtool类是用于获取jdbc连接和释放连接的工具类。
1 package tools; 2 3 import java.sql.*; 4 5 //用于连接数据库的工具类 6 public class DBtool { 7 private static String driver = "com.mysql.jdbc.Driver"; 8 private static String url = "jdbc:mysql://localhost:3306/shopdb"; 9 private static String user = "root"; 10 private static String password = "root"; 11 private static Connection conn = null; 12 13 //获取连接 14 public static Connection getConn() { 15 try{ 16 Class.forName(driver); 17 conn = DriverManager.getConnection(url,user,password); 18 } catch (ClassNotFoundException e) { 19 e.printStackTrace(); 20 } catch (SQLException e) { 21 e.printStackTrace(); 22 } 23 return conn; 24 } 25 26 //关闭连接,释放资源 27 public static void close(Connection conn, PreparedStatement pstm) { 28 try { 29 pstm.close(); 30 } catch (SQLException e) { 31 e.printStackTrace(); 32 } finally { 33 try { 34 conn.close(); 35 } catch (SQLException e) { 36 e.printStackTrace(); 37 } 38 } 39 } 40 }
到这里为止，添加商品的功能已经基本实现。
测试如下：
可以看到GOODS表中有了我们刚才添加的数据。
标签：uniq git import lse ring ble 增删查改 问题 日期
原文地址：https://www.cnblogs.com/blogforvi/p/9381855.html
