SSM实现增删改查

maven仓库配置：

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.19</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.12</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.3</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

application.properties配置：

server.port=8080
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=1234
logging.level.com.yjj.mapper=debug
mybatis.mapper-locations=classpath:com/yjj/mapper/*.xml
#设置数据源
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

实体类Dept：
Dept.java:

/**Getter,Setter,equals,canEqual,hasCode,toString*/
@Data
/**生成一个无参数的构造方法*/
@NoArgsConstructor
/**会生成一个包含所有变量*/
@AllArgsConstructor
public class Dept implements Serializable {
    private int deptno;
    private String dname;
    private String loc;
    public Dept(String dname, String loc) {
        this.dname = dname;
        this.loc = loc;
    }
}

mapper：
DeptMapper.java:

@Mapper
public interface DeptMapper {
 
    /**
     * 查询全部
     * @return
     */
    List<Dept> queryAll();
    /**
     * 根据id删除
     * @param deptno
     */
    void delete(int deptno);

    /**
     * 添加
     * @param dept
     */
    void insert(Dept dept);

    /**
     * 根据id查询
     * @param deptno
     * @return
     */
    Dept queryByDeptno(int deptno);

    /**
     * 修改
     * @param dept
     */
    void update(Dept dept);
}

DeptMapper.xml:

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE mapper PUBLIC "-//http://mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.yjj.mapper.DeptMapper">

    <!--查询全部-->
    <select id="queryAll" resultType="com.yjj.entity.Dept" >
        SELECT
            deptno,
            dname,
            loc
        FROM
            dept
    </select>

    <!-- 根据id删除 -->
    <delete id="delete">
        DELETE
        FROM
            dept
        WHERE
            deptno = #{deptno}
    </delete>

    <!--添加-->
    <insert id="insert" >
        INSERT INTO dept (dname, loc)
        VALUES
            (#{dname}, #{loc})
    </insert>

    <!-- 根据id查询 -->
    <select id="queryByDeptno" resultType="com.yjj.entity.Dept">
        SELECT
            deptno,
            dname,
            loc
        FROM
            dept
        WHERE
            deptno = #{deptno}
    </select>

    <!--修改-->
    <update id="update">
        UPDATE dept
        <set>
            <if test=" dname != null and dname != '' ">
                dname=#{dname},
            </if>
            <if test=" loc != null and loc != '' ">
                loc=#{loc},
            </if>
        </set>
        WHERE
        deptno = #{deptno}
    </update>

</mapper>

service：
DeptService.java:

public interface DeptService {
  
    /**
     * 查询全部
     * @return
     */
    List<Dept> queryAll();
    /**
     * 根据id删除
     * @param deptno
     */
    void delete(int deptno);

    /**
     * 添加
     * @param dept
     */
    void insert(Dept dept);

    /**
     * 根据id查询
     * @param deptno
     * @return
     */
    Dept queryByDeptno(int deptno);

    /**
     * 修改
     * @param dept
     */
    void update(Dept dept);
}

service.impl：
DeptSereviceImpl.java:

@Service
@Transactional
public class DeptServiceImpl implements DeptService {

    @Autowired
    private DeptMapper deptMapper;

    @Override
    public List<Dept> queryAll() {
        return deptMapper.queryAll();
    }

    @Override
    public void delete(int deptno) {
        deptMapper.delete(deptno);
    }

    @Override
    public void insert(Dept dept) {
        deptMapper.insert(dept);
    }

    @Override
    public Dept queryByDeptno(int deptno) {
        return deptMapper.queryByDeptno(deptno);
    }

    @Override
    public void update(Dept dept) {
        deptMapper.update(dept);
    }
}

controller：
DeptController :

@Controller
@RequestMapping("dept")
public class DeptController {

    @Autowired
    private DeptService deptService;

    /**
     * 查询全部
     * @param map
     * @return
     */
    @RequestMapping("queryAll")
    public String queryAll(ModelMap map){
        //System.out.println(deptService.queryAll().toString());
        map.addAttribute("deptList",deptService.queryAll());
        return "query";
    }

    /**
     * 删除
     * @param deptno
     * @return
     */
    @RequestMapping("delete")
    public String delete(int deptno){
        deptService.delete(deptno);
        return "redirect:/dept/queryAll";
    }

    /**
     * 根据id查询
     * @param deptno
     * @param map
     * @return
     */
    @RequestMapping("queryByDeptno")
    public String queryByDeptno(int deptno,ModelMap map){
        map.addAttribute("dept",deptService.queryByDeptno(deptno));
        return "update";
    }

    /**
     * 修改
     * @param dept
     * @return
     */
    @RequestMapping("update")
    public String update(Dept dept){
        deptService.update(dept);
        return "redirect:/dept/queryAll";
    }

    /**
     * 添加
     * @param dept
     * @return
     */
    @RequestMapping("insert")
    public String insert(Dept dept){
        deptService.insert(dept);
        return "redirect:/dept/queryAll";
    }
}

前端页面：
query.html:

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>查询全部</title>
</head>
<body>
<table border="1" cellspacing="0" cellpadding="0" width="600px">
    <tr align="right">
       <td colspan="4"><a th:href="@{/add.html}">添加</a></td>
    </tr>
    <tr align="center">
        <td>deptno</td>
        <td>dname</td>
        <td>loc</td>
        <td>操作</td>
    </tr>
    <tr align="center" th:each="d:${deptList}">
        <td th:text="${d.deptno}">deptno</td>
        <td th:text="${d.dname}">dname</td>
        <td th:text="${d.loc}">loc</td>
        <td>
            <a th:href="@{'/dept/queryByDeptno?deptno='+${d.deptno}}">修改</a>
            <a th:href="@{'/dept/delete?deptno='+${d.deptno}}">删除</a>
        </td>
    </tr>
</table>
</body>
</html>

updata.html:

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>修改</title>
</head>
<body>
<form th:action="@{'/dept/update'}" method="post">
    deptno: <input type="text" name="deptno" th:value="${dept.deptno}" readonly><br>
    dname: <input type="text" name="dname" th:value="${dept.dname}"><br>
    loc: <input type="text" name="loc" th:value="${dept.loc}"><br>
    <input type="submit" value="修改">
</form>
</body>
</html>

add.html:

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>添加</title>
</head>
<body>
<form action="/dept/insert" method="post">
    dname: <input type="text" name="dname" ><br>
    loc: <input type="text" name="loc" ><br>
    <input type="submit" value="添加">
</form>
</body>
</html>

数据库：
dept.sql:

DROP TABLE IF EXISTS `dept`;
CREATE TABLE `dept` (
  `DEPTNO` int(11) NOT NULL AUTO_INCREMENT,
  `DNAME` varchar(255) DEFAULT NULL,
  `loc` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`DEPTNO`)
) ENGINE=InnoDB AUTO_INCREMENT=54 DEFAULT CHARSET=utf8mb4;

-- ----------------------------
-- Records of dept
-- ----------------------------
INSERT INTO `dept` VALUES ('10', 'ACCOUNTING', 'NEW YORK');
INSERT INTO `dept` VALUES ('20', 'RESEARCH', 'DALLAS');
INSERT INTO `dept` VALUES ('30', 'SALES', 'CHICAGO');
INSERT INTO `dept` VALUES ('40', 'OPERATIONS', 'BOSTON');
INSERT INTO `dept` VALUES ('48', '123123', '123123');
INSERT INTO `dept` VALUES ('52', '123', '123');
INSERT INTO `dept` VALUES ('53', '1', '1');

项目结构：
在这里插入图片描述

SSM实现增删改查

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