Day18——准备部门表_部门实体类_维护关系

谁借莪１个温暖的怀抱￠ 2023-07-04 12:59 21阅读 0赞

# 一. 准备 #

后面需要讲自定义映射，所以讲之前需要准备部门表\_部门实体类\_维护关系

# 二. 代码 #

创建表、添加外键、添加约束

-- 创建表
    CREATE TABLE tbl_dept(
      id INT(11) PRIMARY KEY AUTO_INCREMENT,
    	dept_name VARCHAR(50)
    );
    
    
    --给员工表添加外键
    
    ALTER TABLE tbl_employee ADD COLUMN d_id 	INT(11);
    
    --给外键添加约束
    ALTER TABLE tbl_employee ADD CONSTRAINT fk_emp_dept
        FOREIGN KEY (d_id) REFERENCES tbl_dept(id);

创建Department.java

package com.atguigu.mybatis.beans;
    
    public class Department { 
         private Integer id;
         private String department;
    	public Department() { 
    		super();
    		// TODO Auto-generated constructor stub
    	}
    	public Integer getId() { 
    		return id;
    	}
    	public void setId(Integer id) { 
    		this.id = id;
    	}
    	public String getDepartment() { 
    		return department;
    	}
    	public void setDepartment(String department) { 
    		this.department = department;
    	}
    	@Override
    	public String toString() { 
    		return "Department [id=" + id + ", department=" + department + "]";
    	}
         
         
    }

在Employee.java中添加Department

package com.atguigu.mybatis.beans;
    
    public class Employee { 
         private Integer id;
         private String lastName;
         private String email;
         private String gender;
         private Department dept;
         
    	public Employee() { 
    		super();
    		// TODO Auto-generated constructor stub
    	}
    
    	public Employee(Integer id, String lastName, String email, String gender) { 
    		super();
    		this.id = id;
    		this.lastName = lastName;
    		this.email = email;
    		this.gender = gender;
    	}
    	
    	public Department getDept() { 
    		return dept;
    	}
    
    	public void setDept(Department dept) { 
    		this.dept = dept;
    	}
    
    	public Integer getId() { 
    		return id;
    	}
    	
    	public void setId(Integer id) { 
    		this.id = id;
    	}
    	
    	public String getLastName() { 
    		return lastName;
    	}
    	
    	public void setLastName(String lastName) { 
    		this.lastName = lastName;
    	}
    	
    	public String getEmail() { 
    		return email;
    	}
    	
    	public void setEmail(String email) { 
    		this.email = email;
    	}
    	
    	public String getGender() { 
    		return gender;
    	}
    	
    	public void setGender(String gender) { 
    		this.gender = gender;
    	}
    	
    	@Override
    	public String toString() { 
    		return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender + "]";
    	}
         
         
    }