mybatisplus如何自定义xml文件-源码下载

news2024/12/13 10:44:20

1、问题概述？

MybatisPlus通过BaseMapper为我们带来了丰富的基础功能操作，非常使用。

但是在实际的操作中，我们还需要大量的自定义SQL的的时候，这时候就需要自定义xml，从而自定义sql语句。

2、创建工程

2.1、项目结构

2.2、在数据库中创建测试表格

表格需要创建主键

CREATE TABLE `student` (

  `stu_id` varchar(50) NOT NULL,

  `stu_name` varchar(25) DEFAULT NULL,

  `stu_sex` varchar(255) DEFAULT NULL,

  `stu_both` varchar(255) DEFAULT NULL,

  `stu_addr` varchar(200) DEFAULT NULL,

  `stu_pwd` varchar(10) DEFAULT NULL,

  `stu_age` varchar(255) DEFAULT NULL,

  PRIMARY KEY (`stu_id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;



insert  into `student`(`stu_id`,`stu_name`,`stu_sex`,`stu_both`,`stu_addr`,`stu_pwd`,`stu_age`) values

('1001','晓春1','0','1990-05-06 15:27:56','安徽合肥','1001',NULL),

('1002','小春11','1','1998-05-06 15:27:56','安徽黄山','1002',NULL),

('1004','汤晓春','1','1997-05-06 15:27:56','安徽合肥','1004',NULL),

('1005','十一郎','1','1992-05-06 15:27:56','安徽合肥','1005',NULL),

('1006','十二郎','0','1991-05-06 15:27:56','安徽合肥','1006',NULL),

('1007','十三郎','1','1991-05-06 15:27:56','','1006',NULL),

('1008','十四郎','1','1991-05-06 15:27:56',NULL,'1006',NULL),

('1009','十五郎','1','1991-05-06 15:27:56',NULL,'1006',NULL),

('1010','','1','2020-05-08 00:00:00','','',NULL),

('1011',NULL,NULL,NULL,NULL,NULL,NULL);

2.3、工程的pom.xml配置我呢见

重点1：引入springboot+mybatisplus+mysql包

重点2：引入如下配置，否则工程不扫描xml配置文件

<resources>
    <resource>
        <directory>src/main/java</directory>
        <includes><include>**/*.xml</include></includes>
    </resource>
</resources>

【pom.xml配置我呢见】

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.16</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>mybatisplusxml</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>mybatisplusxml</name>
    <description>mybatisplusxml</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>

        <!--mybatisplus包-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3.2</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <annotationProcessorPaths>
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>

        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>
    </build>

</project>

2.4、在application.yml中配置相关信息

spring:
  #数据库连接配置，未使用连接池
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test11?useUnicode=true&characterEncoding=utf-8&useSSL=false&zeroDateTimeBehavior=convertToNull
    username: root
    password: 123456
# 配置mybatis-plus
mybatis-plus:
  configuration:
    #log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: false # 别名配置
  type-aliases-package:  com.*.*.bean
  mapper-locations: classpath:/com/example/mybatisplusxml/mapper/*.xml

2.5、创建Student实体bean

记得添加set和get及构造器

@TableName("student")
public class Student {
    @TableId(value = "stu_id")
    private Integer stu_id;
    private String stu_name;
    private String stu_sex;
    private String stu_age;
    private String stu_addr;
    private String stu_pwd;

}

2.6、创建StudentMapper接口

public interface StudentMapper extends BaseMapper<Student> {
    public List<Student> queryStudentByIdAndName(Student student);
}

2.7、创建StudentMapper.xml配置文件

namespace的地址是StudentMapper接口的全限定名称

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mybatisplusxml.mapper.StudentMapper">
    <!--通过username查询firstname-->
    <select id="queryStudentByIdAndName" resultType="student" parameterType="student">
       select * from student
       where stu_id=#{stu_id} and stu_name=#{stu_name}
    </select>

</mapper>

2.8、创建StudentService业务层类

@Service
public class StudentService {
    @Autowired(required = false)
    private StudentMapper studentMapper;

    public List<Student> queryStudentByIdAndName(Student student){
        return studentMapper.queryStudentByIdAndName(student);
    }

}

2.9、创建StudentController控制层类

@Controller
public class StudentController {
    @Autowired
    private StudentService studentService;

    @RequestMapping("/queryStudentByIdAndName")
    @ResponseBody
    public List<Student> queryStudentByIdAndName(Student student){
        System.out.println(student.getStu_id());
        System.out.println(student.getStu_name());
        return studentService.queryStudentByIdAndName(student);
    }

}

2.10、配置启动类

重点1：@MapperScan注解扫描mapper

@SpringBootApplication
@MapperScan("com.example.mybatisplusxml.mapper")
public class MybatisplusxmlApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisplusxmlApplication.class, args);
    }
}