解决办法 ;还是需要引入xml写SQL语句的方式结合plus实现;
具体实现过程;
现在有两张表;一张年级表 一张学生表;
CREATE TABLE ;grade; (
;gradeid; int NOT NULL AUTO_INCREMENT COMMENT ;年级ID;,
;gradename; varchar(50) NOT NULL COMMENT ;年级名称;,
PRIMARY KEY (;gradeid;)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8mb3;
CREATE TABLE ;student; (
;studentid; int NOT NULL COMMENT ;学号;,
;studentname; varchar(20) NOT NULL DEFAULT ;匿名; COMMENT ;姓名;,
;sex; tinyint(1) DEFAULT ;1; COMMENT ;性别;,
;gradeid; int DEFAULT NULL COMMENT ;年级;,
;phoneNum; varchar(50) NOT NULL COMMENT ;手机;,
;address; varchar(255) DEFAULT NULL COMMENT ;地址;,
;borndate; datetime DEFAULT NULL COMMENT ;生日;,
;email; varchar(50) DEFAULT NULL COMMENT ;邮箱;,
;idCard; varchar(18) DEFAULT NULL COMMENT ;身份证号;,
PRIMARY KEY (;studentid;),
KEY ;FK_gradeid; (;gradeid;),
CONSTRAINT ;FK_gradeid; FOREIGN KEY (;gradeid;) REFERENCES ;grade; (;gradeid;)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3;
;Data
;EqualsAndHashCode(callSuper = false)
;Accessors(chain = true)
;ApiModel(value=;Grade对象;, description=;年级数据表;)
public class Grade implements Serializable {
private static final long serialVersionUID=1L;
;ApiModelProperty(value = ;年级ID;)
;TableId(value = ;gradeid;, type = IdType.AUTO)
private Integer gradeid;
;ApiModelProperty(value = ;年级名称;)
private String gradename;
}
;Data
public class GradeVO {
private String gradename;//年级名称
private String studentname;//学生姓名
private String address;//住址
}
;Data
;EqualsAndHashCode(callSuper = false)
;Accessors(chain = true)
;ApiModel(value=;Student对象;, description=;学生数据表;)
public class Student implements Serializable {
private static final long serialVersionUID=1L;
;ApiModelProperty(value = ;学号;)
;TableId(value = ;studentid;, type = IdType.ASSIGN_UUID)
private Integer studentid;
;ApiModelProperty(value = ;姓名;)
private String studentname;
;ApiModelProperty(value = ;性别;)
private Boolean sex;
;ApiModelProperty(value = ;年级;)
private Integer gradeid;
;ApiModelProperty(value = ;手机;)
;TableField(;phoneNum;)
private String phoneNum;
;ApiModelProperty(value = ;地址;)
private String address;
;ApiModelProperty(value = ;生日;)
private Date borndate;
;ApiModelProperty(value = ;邮箱;)
private String email;
;ApiModelProperty(value = ;身份证号;)
;TableField(;idCard;)
private String idCard;
}
;Mapper
;Repository
public interface GradeMapper extends BaseMapper<Grade> {
//与数据库交互
IPage<GradeVO> findPage(IPage<GradeVO> page, ;Param(Constants.WRAPPER) QueryWrapper<GradeVO> wrapper);
}
<?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.xxx.xxx.mapper.GradeMapper;>
<select id=;findPage; resultType=;com.xxx.xxx.entity.grade.GradeVO;>
SELECT
*
FROM
grade inner join student
on
grade.gradeid=student.gradeid
${ew.customSqlSegment}
<!--<where>-->
<!--${ew.SqlSegment} -->
<!--</where>-->
</select>
</mapper>
public interface GradeService extends IService<Grade> {
/**
*联表分页查询xml
* ;param page
* ;param queryWrapper
* ;return
*/
IPage<GradeVO> findPage(Page<GradeVO> page, QueryWrapper<GradeVO> queryWrapper);
}
;Service
public class GradeServiceImpl extends ServiceImpl<GradeMapper, Grade> implements GradeService {
;Autowired
private GradeMapper gradeMapper;
;Override
public IPage<GradeVO> findPage(Page<GradeVO> page, QueryWrapper<GradeVO> queryWrapper) {
return baseMapper.findPage(page, queryWrapper);
}
}
;RestController
;RequestMapping(;/grade;)
public class GradeController {
;Autowired
private GradeService gradeService;
/**
* 复杂查询
*/
;GetMapping(;pageXml/{corund}/{limit};)
public R pageXml(;PathVariable(;corund;)Integer corund,;PathVariable(;limit;)Integer limit){
Page<GradeVO> page = new Page<>(corund,limit);
IPage<GradeVO> GradePage = gradeService.findPage(page, new QueryWrapper<>());
return R.ok().data(;GradePage;,GradePage);
}
}
测试api接口;http://localhost:8080/grade/pageXml/1/5
来源;mybatis-plus 多表查询_;Jerry-的博客-CSDN博客_mybatis plus多表查询