diff --git a/README.md b/README.md
index cd3c994..403e326 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,12 @@
 # Homework-entities
 *网安实训作业*
 
-# 20230316
+# 2023-03-16
 - 初始化项目
-# 20230322
+# 2023-03-22
 - 增加实体类
 - 删除.idea文件
-# 20230326
+# 2023-03-26
 - 完善实体类
 - 我靠,折腾了一晚上,提交了十几次,终于提交时把.idea这个文件给忽略了
   - 方法:在`.gitgnore`文件中添加
@@ -19,7 +19,20 @@
   - `update`一下远端项目
   - `push`代码
 - 我好菜。。。
-# 20230327
+# 2023-03-27
 - 完善了一下实体类,发现商家那一部分漏了一点东西,给它补上了
 - 另外就是为什么`.idea`文件我已经取消提交了,为啥本地的`commit`里面还会有有啊……无语了
-- 是不是跟`git`八字不合。。。
\ No newline at end of file
+- 是不是跟`git`八字不合。。。
+# 2023-03-29
+- 添加`JDBC`驱动,连接数据库
+# 2023-05-04
+- 创建数据库表,并成功连接
+- 调整实体类与数据库对应的结构,修改外键
+- 调整项目结构
+- 完成DAO层抽象接口
+- 完成MerchantsDAO和UserDAO具体功能
+# 2023-05-05
+- Debug MerchantsDAO 按ID查询功能
+- 搭建shellUI的大体框架
+- 完成UserDAO具体功能
+- 第一次测试
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index fe2baff..ba0c763 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,36 +1,47 @@
 
-  4.0.0
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    4.0.0
 
-  org.example
-  JavaEle
-  1.0-SNAPSHOT
-  jar
+    org.example
+    JavaElm
+    1.0-SNAPSHOT
+    jar
 
-  JavaEle
-  https://maven.apache.org
+    JavaEle
+    https://maven.apache.org
 
-  
-    UTF-8
-    17
-    17
-    17
-  
+    
+        UTF-8
+        17.0.6
+        17.0.6
+        17.0.6
+    
 
-  
-    
-      junit
-      junit
-      4.13.2
-      test
-    
+    
+        
+            junit
+            junit
+            4.13.2
+            test
+        
 
-    
-      org.projectlombok
-      lombok
-      true
-      1.18.26
-    
+        
+            org.projectlombok
+            lombok
+            true
+            1.18.26
+        
 
-  
+        
+            com.microsoft.sqlserver
+            mssql-jdbc
+            12.2.0.jre11
+        
+        
+            org.jetbrains
+            annotations
+            20.1.0
+            compile
+        
+    
 
diff --git a/src/main/java/dao/IndentAbstractDAO.java b/src/main/java/dao/IndentAbstractDAO.java
new file mode 100644
index 0000000..ef85f83
--- /dev/null
+++ b/src/main/java/dao/IndentAbstractDAO.java
@@ -0,0 +1,4 @@
+package dao;
+
+public interface IndentAbstractDAO {
+}
diff --git a/src/main/java/dao/abstractDAO.java b/src/main/java/dao/abstractDAO.java
new file mode 100644
index 0000000..f167625
--- /dev/null
+++ b/src/main/java/dao/abstractDAO.java
@@ -0,0 +1,13 @@
+package dao;
+
+import java.util.List;
+
+public interface abstractDAO {
+    int insert(T t); //增
+
+    int delete(T t);//删
+
+    int update(T t);//改
+
+    List search(T t);//查
+}
diff --git a/src/main/java/dao/indentItemAbstractDAO.java b/src/main/java/dao/indentItemAbstractDAO.java
new file mode 100644
index 0000000..3e41e28
--- /dev/null
+++ b/src/main/java/dao/indentItemAbstractDAO.java
@@ -0,0 +1,7 @@
+package dao;
+
+import entities.indentItem;
+
+public interface indentItemAbstractDAO extends abstractDAO {
+
+}
diff --git a/src/main/java/dao/merchantsAbstractDAO.java b/src/main/java/dao/merchantsAbstractDAO.java
new file mode 100644
index 0000000..6e27f93
--- /dev/null
+++ b/src/main/java/dao/merchantsAbstractDAO.java
@@ -0,0 +1,8 @@
+package dao;
+
+import entities.Merchants;
+
+public interface merchantsAbstractDAO extends abstractDAO {
+    //根据id查询商家
+    Merchants searchMerchantByID(Long id);
+}
diff --git a/src/main/java/dao/specification/merchantsDAO.java b/src/main/java/dao/specification/merchantsDAO.java
new file mode 100644
index 0000000..9c222c7
--- /dev/null
+++ b/src/main/java/dao/specification/merchantsDAO.java
@@ -0,0 +1,136 @@
+package dao.specification;
+
+import dao.merchantsAbstractDAO;
+import org.jetbrains.annotations.NotNull;
+import entities.Merchants;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.sql.*;
+
+import static util.SQLDatabaseConnection.close;
+import static util.SQLDatabaseConnection.getConnection;
+
+public class merchantsDAO implements merchantsAbstractDAO {
+    private Connection connection = null;
+    private PreparedStatement preparedStatement = null;
+    private ResultSet resultSet = null;
+
+    //通过id寻找商家
+    @Override
+    public Merchants searchMerchantByID(Long id) {
+        Merchants merchants = null;
+        String selectID_sql = "select * from Merchants where id = ?";
+        try {
+            connection = getConnection();
+            preparedStatement = connection.prepareStatement(selectID_sql);
+            preparedStatement.setLong(1, id);
+            resultSet = preparedStatement.executeQuery();
+
+            while (resultSet.next()) {
+                merchants = new Merchants();
+                merchants.setId(resultSet.getLong("id"));
+                merchants.setName(resultSet.getString("name"));
+                merchants.setAddress(resultSet.getString("address"));
+                merchants.setDescription(resultSet.getString("description"));
+                merchants.setPhoneNumber(resultSet.getString("phoneNumber"));
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+        return merchants;
+    }
+
+    //新加商家
+    @Override
+    public int insert(@NotNull Merchants merchants) {
+        int flag = 0;
+        try {
+            connection = getConnection();
+            String insert_sql = "insert into Merchants(name,address,description,phoneNumber) values(?,?,?,?)";
+            preparedStatement = connection.prepareStatement(insert_sql);
+
+            preparedStatement.setString(1, merchants.getName());
+            preparedStatement.setString(2, merchants.getAddress());
+            preparedStatement.setString(3, merchants.getDescription());
+            preparedStatement.setString(4, merchants.getPhoneNumber());
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+        return flag;
+    }
+
+    //删除商家
+    @Override
+    public int delete(Merchants merchants) {
+        int flag = 0;
+        try {
+            connection = getConnection();
+            String delete_sql = "delete from Merchants where id = ?";
+            preparedStatement = connection.prepareStatement(delete_sql);
+            preparedStatement.setLong(1, merchants.getId());
+            flag = preparedStatement.executeUpdate();
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+        return flag;
+    }
+
+    //更新信息
+    @Override
+    public int update(@NotNull Merchants merchants) {
+        int flag;
+        String update_sql = "update Merchants " +
+                "set name = ?, address = ?, description = ?, phoneNumber= ? " +
+                "where id = ?";
+        try {
+            connection = getConnection();
+            preparedStatement = connection.prepareStatement(update_sql);
+
+            preparedStatement.setString(1, merchants.getName());
+            preparedStatement.setString(2, merchants.getAddress());
+            preparedStatement.setString(3, merchants.getDescription());
+            preparedStatement.setString(4, merchants.getPhoneNumber());
+            preparedStatement.setLong(5, merchants.getId());
+
+            flag = preparedStatement.executeUpdate(update_sql);
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+        return flag;
+    }
+
+    //查询所有商家
+    @Override
+    public List search(Merchants merchants) {
+        List list = new ArrayList<>();
+        try {
+            connection = getConnection();
+            String selectAll_sql = "select * from Merchants";
+            preparedStatement = connection.prepareStatement(selectAll_sql);
+            resultSet = preparedStatement.executeQuery();
+
+            while (resultSet.next()) {
+                merchants.setId(resultSet.getLong("id"));
+                merchants.setName(resultSet.getString("name"));
+                merchants.setPhoneNumber(resultSet.getString("phoneNumber"));
+                merchants.setAddress(resultSet.getString("address"));
+                merchants.setDescription(resultSet.getString("description"));
+                list.add(merchants);
+            }
+
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+        return list;
+    }
+
+}
diff --git a/src/main/java/dao/specification/userDAO.java b/src/main/java/dao/specification/userDAO.java
new file mode 100644
index 0000000..892a061
--- /dev/null
+++ b/src/main/java/dao/specification/userDAO.java
@@ -0,0 +1,119 @@
+package dao.specification;
+
+import dao.userAbstractDAO;
+import entities.Users;
+import org.jetbrains.annotations.NotNull;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+import static util.SQLDatabaseConnection.getConnection;
+import static util.SQLDatabaseConnection.close;
+
+public class userDAO implements userAbstractDAO {
+    private Connection connection = null;
+    private PreparedStatement preparedStatement = null;
+    private ResultSet resultSet = null;
+
+    //@TODO UserDAO 插入功能
+    @Override
+    public int insert(Users users) {
+
+        return 0;
+    }
+
+    @Override
+    public int delete(@NotNull Users users) {
+        int flag;
+        try {
+            connection = getConnection();
+            String delete_sql = "delete from Users where id=?";
+            preparedStatement = connection.prepareStatement(delete_sql);
+            preparedStatement.setLong(1, users.getId());
+            flag = preparedStatement.executeUpdate();
+
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+
+        return flag;
+    }
+
+    @Override
+    public int update(@NotNull Users users) {
+        int flag = 0;
+        try {
+            connection = getConnection();
+            String update_sql = "update Users " +
+                    "set name = ?, phoneNumber = ?, address = ? " +
+                    "where id = ?";
+            preparedStatement = connection.prepareStatement(update_sql);
+            preparedStatement.setString(1,users.getName());
+            preparedStatement.setString(2,users.getPhoneNumber());
+            preparedStatement.setString(3,users.getAddress());
+            preparedStatement.setLong(4,users.getId());
+
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+        return flag;
+    }
+
+    //查询所有用户
+    @Override
+    public List search(Users users) {
+        List list = new ArrayList<>();
+
+        try {
+            connection = getConnection();
+            String selectAll_sql = "select * from Users";
+            preparedStatement = connection.prepareStatement(selectAll_sql);
+            preparedStatement.executeQuery();
+
+            while (resultSet.next()) {
+                users.setName(resultSet.getString("name"));
+                users.setPhoneNumber(resultSet.getString("phoneNumber"));
+                users.setAddress(resultSet.getString("address"));
+                list.add(users);
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+        return list;
+    }
+
+    //用ID查询用户
+    @Override
+    public Users searchUsersByID(Long id) {
+        Users user = null;
+        String selectID_sql = "select * from Users where id = ?";
+        try {
+            connection = getConnection();
+            preparedStatement = connection.prepareStatement(selectID_sql);
+            preparedStatement.setLong(1, id);
+            resultSet = preparedStatement.executeQuery();
+
+            while (resultSet.next()) {
+                user = new Users();
+                user.setId(resultSet.getLong("id"));
+                user.setName(resultSet.getString("name"));
+                user.setPhoneNumber(resultSet.getString("phoneNumber"));
+                user.setAddress(resultSet.getString("address"));
+            }
+
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } finally {
+            close(connection, preparedStatement, resultSet);
+        }
+        return user;
+    }
+}
diff --git a/src/main/java/dao/userAbstractDAO.java b/src/main/java/dao/userAbstractDAO.java
new file mode 100644
index 0000000..740ff21
--- /dev/null
+++ b/src/main/java/dao/userAbstractDAO.java
@@ -0,0 +1,8 @@
+package dao;
+
+import entities.Users;
+
+public interface userAbstractDAO extends abstractDAO {
+    //根据ID查询用户
+    Users searchUsersByID(Long id);
+}
diff --git a/src/main/java/entities/Indent.java b/src/main/java/entities/Indent.java
index 75cd81b..e9aaf6a 100644
--- a/src/main/java/entities/Indent.java
+++ b/src/main/java/entities/Indent.java
@@ -2,13 +2,17 @@ package entities;
 
 import lombok.Data;
 
+import java.util.Date;
+
 //订单类
 @Data
 public class Indent {
     private Long id;//订单ID
-    private indentItem indentItemID;//外键,菜品ID
+
     private Users userID;//外键,下单用户ID
     private Merchants merchantsID;//外键,餐厅ID
-    private Float allPrice;//菜品总价
 
+    private Float allPrice;//菜品总价
+    Date createdDate;//订单创建时间
+    String message;//下单备注
 }
diff --git a/src/main/java/entities/Merchants.java b/src/main/java/entities/Merchants.java
index 85cdd7e..3785e1b 100644
--- a/src/main/java/entities/Merchants.java
+++ b/src/main/java/entities/Merchants.java
@@ -5,10 +5,19 @@ import lombok.Data;
 //商家类
 @Data
 public class Merchants {
-    private Long id;//商家编号
+    private Long id;//主键,商家编号
+
     private String name;//店铺名字
     private String address;//店铺地址
     private String description;//店铺描述
     private String phoneNumber;//商家联系方式
-    private Indent IndentID;//外键,订单ID
+
+    @Override
+    public String toString() {
+        return "\n商家编号:" + this.id +
+                "\n店铺名字:" + this.name +
+                "\n店铺地址:" + this.address +
+                "\n店铺描述:" + this.description +
+                "\n联系方式:" + this.phoneNumber;
+    }
 }
diff --git a/src/main/java/entities/Users.java b/src/main/java/entities/Users.java
index ce8d221..e3d54c8 100644
--- a/src/main/java/entities/Users.java
+++ b/src/main/java/entities/Users.java
@@ -5,8 +5,18 @@ import lombok.Data;
 //用户类
 @Data
 public class Users {
-    private Long id;//用户ID
+    private Long id;//主键,用户ID
+    private String password;//用户密码
     private String name;//用户姓名
     private String phoneNumber;//用户联系方式
     private String address;//家庭住址
+
+    @Override
+    public String toString() {
+        return "\n用户编号:" + this.id +
+                "\n用户姓名:" + this.name +
+                "\n家庭地址:" + this.address +
+                "\n联系方式:" + this.phoneNumber;
+    }
+
 }
diff --git a/src/main/java/entities/indentItem.java b/src/main/java/entities/indentItem.java
index 1786401..74ca446 100644
--- a/src/main/java/entities/indentItem.java
+++ b/src/main/java/entities/indentItem.java
@@ -4,10 +4,12 @@ import lombok.Data;
 //订单中的菜品
 @Data
 public class indentItem {
-    private Long id;//菜品ID
+    private Long id;//主键,菜品ID
     private String name;//菜品名字
     private Float initialPrice;//菜品原价
     private Float discount;//折扣
     private Float finalPrice;//最终价格
     private String description;//菜品描述
+
+    private Indent indentID;//订单ID
 }
\ No newline at end of file
diff --git a/src/main/java/example/App.java b/src/main/java/example/App.java
index fba0024..9a87d1d 100644
--- a/src/main/java/example/App.java
+++ b/src/main/java/example/App.java
@@ -1,7 +1,9 @@
 package example;
 
+import entities.*;
+
 public class App {
     public static void main(String[] args) {
-        System.out.println("Hello World!");
+        System.out.println("你好世界!Hello World!");
     }
 }
diff --git a/src/main/java/example/shellUI.java b/src/main/java/example/shellUI.java
new file mode 100644
index 0000000..f3fb82b
--- /dev/null
+++ b/src/main/java/example/shellUI.java
@@ -0,0 +1,55 @@
+package example;
+
+import com.microsoft.sqlserver.jdbc.StringUtils;
+import dao.*;
+import dao.specification.*;
+
+import java.util.Scanner;
+
+public class shellUI {
+    public static void main(String[] args) {
+        run();
+    }
+
+    public static void run() {
+        Scanner reader = new Scanner(System.in);
+        System.out.println("""
+                ------------------------------------------
+                ----------------后台管理系统----------------
+                ------------------------------------------
+                """);
+        System.out.println("""
+                请选择你要进行的功能
+                1.商家管理
+                2.用户管理
+                """);
+        //
+        int chose1;
+        while (true) {
+            if (reader.hasNextInt()) {
+                chose1 = reader.nextInt();
+                break;
+            } else {
+                System.out.println("你的输入有误,请重新输入!");
+            }
+        }
+        //@TODO 2023-05-05 shellUI功能选择
+        int chose2;
+        switch (chose1) {
+            case 1:
+                System.out.println("""
+                        请选择你想使用的功能:
+                        1.
+                        2.
+                        3.
+                        4.
+                        5.
+                        """);
+
+                break;
+            case 2:
+        }
+
+
+    }
+}
diff --git a/src/main/java/util/SQLDatabaseConnection.java b/src/main/java/util/SQLDatabaseConnection.java
new file mode 100644
index 0000000..d44d04c
--- /dev/null
+++ b/src/main/java/util/SQLDatabaseConnection.java
@@ -0,0 +1,47 @@
+package util;
+
+import java.sql.*;
+
+public class SQLDatabaseConnection {
+    // Connect to database
+    private static final String connectionUrl =
+            "jdbc:sqlserver://152.136.182.168:1433;"
+                    + "database=Elm;"
+                    + "user=guest@152.136.182.168;"
+                    + "password=20230504#Guest;"
+                    + "encrypt=true;"
+                    + "trustServerCertificate=false;"
+                    + "loginTimeout=30;";
+
+    public static Connection getConnection() {
+        Connection connection = null;
+        try {
+            // Code here.
+            connection = DriverManager.getConnection(connectionUrl);
+        }
+        // Handle any errors that may have occurred.
+        catch (SQLException e) {
+            e.printStackTrace();
+        }
+        return connection;
+    }
+
+    //释放资源
+    public static void close(Connection connection, Statement statement, ResultSet resultSet) {
+        try {
+            if (resultSet != null) {
+                resultSet.close();
+            }
+            if (statement != null) {
+                statement.close();
+            }
+            if (connection != null) {
+                connection.close();
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+    }
+
+}