一、分页

1、配置分页插件

    service-edu模块下的EduConfig类

package com.atguigu.eduservice.config;
@EnableTransactionManagement
@Configuration
@MapperScan("com.atguigu.eduservice.mapper")
public class EduConfig {
    /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }
}

2、分页Controller方法

    EduTeacherController中添加分页方法

@ApiOperation(value = "分页讲师列表")
@GetMapping("pageTeacher/{current}/{limit}")
public R pageListTeacher(
    @ApiParam(name = "page", value = "当前页码", required = true)
    @PathVariable Long page,
    @ApiParam(name = "limit", value = "每页记录数", required = true)
    @PathVariable Long limit){
    //创建page对象
    Page<Teacher> pageParam = new Page<>(page, limit);
    //调用方法实现分页
    //调用方法时候，底层封装，把分页所有数据封装到pageTeacher对象里面
    teacherService.page(pageParam, null);
    List<Teacher> records = pageParam.getRecords();       //数据list集合
    long total = pageParam.getTotal();                    //总记录数
    //Map map = new HashMap();
    //map.put("total",total);
    //map.put("rows",records);
    //return R.ok().data(map);
    return  R.ok().data("total", total).data("rows", records);
}

3、Swagger中测试

二、条件查询

        根据讲师名称name，讲师头衔level、讲师入驻时间gmt_create（时间段）查询<br />![图片.png](https://cdn.nlark.com/yuque/0/2021/png/22523384/1635951303433-62365708-ae65-4974-972d-fcb18e1c368a.png#clientId=u29d9fa0e-fa8d-4&from=paste&height=510&id=u1c21ae08&margin=%5Bobject%20Object%5D&name=%E5%9B%BE%E7%89%87.png&originHeight=510&originWidth=1232&originalType=binary&ratio=1&size=24904&status=done&style=none&taskId=ub7a6dcd3-3d54-4a46-9aab-2c238e44da4&width=1232)

1、创建查询对象

创建com.atguigu.eduservice.entity.vo包，创建TeacherQuery.java查询对象

package com.atguigu.eduservice.entity.vo;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
@ApiModel(value = "Teacher查询对象", description = "讲师查询对象封装")
@Data
public class TeacherQuery {
    @ApiModelProperty(value = "教师名称,模糊查询")
    private String name;
    @ApiModelProperty(value = "头衔 1高级讲师 2首席讲师")
    private Integer level;
    @ApiModelProperty(value = "查询开始时间", example = "2019-01-01 10:10:10")
    private String begin;//注意，这里使用的是String类型，前端传过来的数据无需进行类型转换
    @ApiModelProperty(value = "查询结束时间", example = "2019-12-01 10:10:10")
    private String end;
}

2、service

2.1 接口

package com.guli.edu.service;
public interface TeacherService extends IService<Teacher> {
    void pageQuery(Page<EduTeacher> pageParam, TeacherQuery teacherQuery);
}

2.2 实现

package com.guli.edu.service.impl;
@Service
public class TeacherServiceImpl extends ServiceImpl<TeacherMapper, EduTeacher> implements TeacherService {
    @Override
    public void pageQuery(Page<EduTeacher> pageParam, TeacherQuery teacherQuery) {
        QueryWrapper<EduTeacher> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByAsc("gmt_create");
        if (teacherQuery == null){
            baseMapper.selectPage(pageParam, queryWrapper);
            return;
        }
        String name = teacherQuery.getName();
        Integer level = teacherQuery.getLevel();
        String begin = teacherQuery.getBegin();
        String end = teacherQuery.getEnd();
        if (!StringUtils.isEmpty(name)) {
            queryWrapper.like("name", name);
        }
        if (!StringUtils.isEmpty(level) ) {
            queryWrapper.eq("level", level);
        }
        if (!StringUtils.isEmpty(begin)) {
            queryWrapper.ge("gmt_create", begin);
        }
        if (!StringUtils.isEmpty(end)) {
            queryWrapper.le("gmt_create", end);
        }
        baseMapper.selectPage(pageParam, queryWrapper);
    }
}

3、controller

EduTeacherController中新增pageTeacherCondition方法：
增加参数TeacherQuery，非必选

@ApiOperation(value = "分页讲师列表")
@GetMapping("{page}/{limit}")
public R pageTeacherCondition(
                            @ApiParam(name = "page", value = "当前页码", required = true)
                            @PathVariable Long page,
                               @ApiParam(name = "limit", value = "每页记录数", required = true)
                            @PathVariable Long limit,
                            @ApiParam(name = "teacherQuery", value = "查询对象", required = false)
                            TeacherQuery teacherQuery){
    //创建page对象
    Page<EduTeacher> pageParam = new Page<>(page, limit);
    //调用方法实现条件查询分页
    teacherService.pageQuery(pageParam, teacherQuery);
    List<EduTeacher> records = pageParam.getRecords();
    long total = pageParam.getTotal();
    return  R.ok().data("total", total).data("rows", records);
}

package com.atguigu.eduservice.controller;
@Api(description="讲师管理")
@RestController
@RequestMapping("/eduservice/teacher")
public class EduTeacherController {
    //把service注入
    @Autowired
    private EduTeacherService teacherService;
    //4 条件查询带分页的方法
    @PostMapping("pageTeacherCondition/{current}/{limit}")
    public R pageTeacherCondition(@PathVariable long current,               //当前页码
                                  @PathVariable long limit,                 //每页记录数
                                  @RequestBody(required = false)  TeacherQuery teacherQuery) {
        //创建page对象
        Page<EduTeacher> pageTeacher = new Page<>(current,limit);
        //构建条件
        QueryWrapper<EduTeacher> wrapper = new QueryWrapper<>();
       // 多条件组合查询
        // mybatis学过 动态sql
        String name = teacherQuery.getName();
        Integer level = teacherQuery.getLevel();
        String begin = teacherQuery.getBegin();
        String end = teacherQuery.getEnd();
        //判断条件值是否为空，如果不为空拼接条件
        if(!StringUtils.isEmpty(name)) {
            //构建条件
            wrapper.like("name",name);
        }
        if(!StringUtils.isEmpty(level)) {
            wrapper.eq("level",level);
        }
        if(!StringUtils.isEmpty(begin)) {
            wrapper.ge("gmt_create",begin);
        }
        if(!StringUtils.isEmpty(end)) {
            wrapper.le("gmt_create",end);
        }
        //排序
        wrapper.orderByDesc("gmt_create");
        //调用方法实现条件查询分页
        teacherService.page(pageTeacher,wrapper);
        long total = pageTeacher.getTotal();                    //总记录数
        List<EduTeacher> records = pageTeacher.getRecords();    //数据list集合
        return R.ok().data("total",total).data("rows",records);
    }
}

4、Swagger中测试