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准备工作
删除操作
预编译SQL
增加操作
获取返回的主键 更新操作 准备工作 准备数据库表 emp创建一个新的springboot工程#xff0c;选择引入对应的起步依赖#xff08;mybatis、mysql驱动、lombok#xff09;application.properties中引入数据库连接信息创建对应…目录
准备工作
删除操作
预编译SQL
增加操作
获取返回的主键 更新操作 准备工作 准备数据库表 emp创建一个新的springboot工程选择引入对应的起步依赖mybatis、mysql驱动、lombokapplication.properties中引入数据库连接信息创建对应的实体类 Emp实体类属性采用驼峰命名准备Mapper接口 EmpMapper 目录结构如下 建表语句如下
-- 部门管理
create table dept(id int unsigned primary key auto_increment comment 主键ID,name varchar(10) not null unique comment 部门名称,create_time datetime not null comment 创建时间,update_time datetime not null comment 修改时间
) comment 部门表;insert into dept (id, name, create_time, update_time) values(1,学工部,now(),now()),(2,教研部,now(),now()),(3,咨询部,now(),now()), (4,就业部,now(),now()),(5,人事部,now(),now());-- 员工管理
create table emp (id int unsigned primary key auto_increment comment ID,username varchar(20) not null unique comment 用户名,password varchar(32) default 123456 comment 密码,name varchar(10) not null comment 姓名,gender tinyint unsigned not null comment 性别, 说明: 1 男, 2 女,image varchar(300) comment 图像,job tinyint unsigned comment 职位, 说明: 1 班主任,2 讲师, 3 学工主管, 4 教研主管, 5 咨询师,entrydate date comment 入职时间,dept_id int unsigned comment 部门ID,create_time datetime not null comment 创建时间,update_time datetime not null comment 修改时间
) comment 员工表;INSERT INTO emp(id, username, password, name, gender, image, job, entrydate,dept_id, create_time, update_time) VALUES(1,jinyong,123456,金庸,1,1.jpg,4,2000-01-01,2,now(),now()),(2,zhangwuji,123456,张无忌,1,2.jpg,2,2015-01-01,2,now(),now()),(3,yangxiao,123456,杨逍,1,3.jpg,2,2008-05-01,2,now(),now()),(4,weiyixiao,123456,韦一笑,1,4.jpg,2,2007-01-01,2,now(),now()),(5,changyuchun,123456,常遇春,1,5.jpg,2,2012-12-05,2,now(),now()),(6,xiaozhao,123456,小昭,2,6.jpg,3,2013-09-05,1,now(),now()),(7,jixiaofu,123456,纪晓芙,2,7.jpg,1,2005-08-01,1,now(),now()),(8,zhouzhiruo,123456,周芷若,2,8.jpg,1,2014-11-09,1,now(),now()),(9,dingminjun,123456,丁敏君,2,9.jpg,1,2011-03-11,1,now(),now()),(10,zhaomin,123456,赵敏,2,10.jpg,1,2013-09-05,1,now(),now()),(11,luzhangke,123456,鹿杖客,1,11.jpg,5,2007-02-01,3,now(),now()),(12,hebiweng,123456,鹤笔翁,1,12.jpg,5,2008-08-18,3,now(),now()),(13,fangdongbai,123456,方东白,1,13.jpg,5,2012-11-01,3,now(),now()),(14,zhangsanfeng,123456,张三丰,1,14.jpg,2,2002-08-01,2,now(),now()),(15,yulianzhou,123456,俞莲舟,1,15.jpg,2,2011-05-01,2,now(),now()),(16,songyuanqiao,123456,宋远桥,1,16.jpg,2,2010-01-01,2,now(),now()),(17,chenyouliang,123456,陈友谅,1,17.jpg,NULL,2015-03-21,NULL,now(),now()); Emp.java内容如下
package com.itheima.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.time.LocalDate;
import java.time.LocalDateTime;Data
NoArgsConstructor
AllArgsConstructor
public class Emp {private Integer id;private String username;private String password;private String name;private Short gender;private String image;private Short job;private LocalDate entrydate;private Integer deptId;private LocalDateTime createTime;private LocalDateTime updateTime;
}删除操作 EmpMapper内容如下
package com.itheima.mapper;import org.apache.ibatis.annotations.*;Mapper
public interface EmpMapper {//根据id删除数据Delete(delete from emp where id #{id})public void delete(Integer id);//可以有返回值返回影响的记录数,将void改成int}SpringbootMybatisCrudApplicationTests.java内容如下
package com.itheima;import com.itheima.mapper.EmpMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;SpringBootTest
class SpringbootMybatisCrudApplicationTests {Autowiredprivate EmpMapper empMapper;Testpublic void testDelete(){empMapper.delete(17);}}运行后发现删除成功 预编译SQL 性能更高更安全(防止SQL注入) 可以在application.properties文件中加入如下指令可以在控制台查看mybatis日志
#配置mybatis的日志指定输出到控制台
mybatis.configuration.log-implorg.apache.ibatis.logging.stdout.StdOutImpl
在mybatis的Mapper接口中声明的SQL语句使用的#{}占位符#{}会被替代生成预编译SQL 增加操作
EmpMapper内容如下
package com.itheima.mapper;import com.itheima.pojo.Emp;
import org.apache.ibatis.annotations.*;Mapper
public interface EmpMapper {//根据id删除数据Insert(insert into emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time) values (#{username},#{name},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime}))//注意驼峰命名法public void insert(Emp emp);}SpringbootMybatisCrudApplicationTests.java内容如下
package com.itheima;import com.itheima.mapper.EmpMapper;
import com.itheima.pojo.Emp;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import java.time.LocalDate;
import java.time.LocalDateTime;SpringBootTest
class SpringbootMybatisCrudApplicationTests {Autowiredprivate EmpMapper empMapper;Testpublic void testInsert(){Emp emp new Emp();emp.setUsername(aw);emp.setName(awaw);emp.setImage(1.jpg);emp.setGender((short)1);emp.setJob((short)1);emp.setEntrydate(LocalDate.of(2000,1,1));emp.setCreateTime(LocalDateTime.now());emp.setUpdateTime(LocalDateTime.now());emp.setDeptId(1);empMapper.insert(emp);}}运行后发现新增成功 获取返回的主键 Options(keyProperty id,useGeneratedKeys true) 会自动将生成的主键值赋值给emp对象的id属性 EmpMapper内容如下
package com.itheima.mapper;import com.itheima.pojo.Emp;
import org.apache.ibatis.annotations.*;Mapper
public interface EmpMapper {//根据id删除数据Options(keyProperty id,useGeneratedKeys true)//会自动将生成的主键值赋值给emp对象的id属性Insert(insert into emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time) values (#{username},#{name},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime}))public void insert(Emp emp);}SpringbootMybatisCrudApplicationTests.java内容如下
package com.itheima;import com.itheima.mapper.EmpMapper;
import com.itheima.pojo.Emp;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import java.time.LocalDate;
import java.time.LocalDateTime;SpringBootTest
class SpringbootMybatisCrudApplicationTests {Autowiredprivate EmpMapper empMapper;Testpublic void testInsert(){Emp emp new Emp();emp.setUsername(tom3);emp.setName(tom3);emp.setImage(1.jpg);emp.setGender((short)1);emp.setJob((short)1);emp.setEntrydate(LocalDate.of(2000,1,1));emp.setCreateTime(LocalDateTime.now());emp.setUpdateTime(LocalDateTime.now());emp.setDeptId(1);empMapper.insert(emp);System.out.println(emp.getId());}}
运行结果如下发现返回了主键 更新操作
EmpMapper内容如下
package com.itheima.mapper;import com.itheima.pojo.Emp;
import org.apache.ibatis.annotations.*;Mapper
public interface EmpMapper {//根据id删除数据Update(update emp set username #{username}, name #{name}, gender #{gender}, image #{image}, job #{job}, entrydate #{entrydate}, dept_id #{deptId},update_time #{updateTime} where id #{id})public void update(Emp emp);}SpringbootMybatisCrudApplicationTests.java内容如下
package com.itheima;import com.itheima.mapper.EmpMapper;
import com.itheima.pojo.Emp;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import java.time.LocalDate;
import java.time.LocalDateTime;SpringBootTest
class SpringbootMybatisCrudApplicationTests {Autowiredprivate EmpMapper empMapper;Testpublic void testUpdate(){Emp emp new Emp();emp.setId(21);emp.setUsername(hi);emp.setName(hello);emp.setImage(2.jpg);emp.setGender((short)1);emp.setJob((short)1);emp.setEntrydate(LocalDate.of(2000,1,1));emp.setCreateTime(LocalDateTime.now());emp.setUpdateTime(LocalDateTime.now());emp.setDeptId(1);empMapper.update(emp);}}查询emp数据表 运行之后发现更改成功
