【搬运】谷粒学院文档-04：分页和条件查询接口开发

一、分页

1、MyBatisPlusConfig中配置分页插件

/**
 * 分页插件
 */
@Bean
public PaginationInterceptor paginationInterceptor() {
    return new PaginationInterceptor();
}

2、分页Controller方法

TeacherAdminController中添加分页方法

@ApiOperation(value = "分页讲师列表")
@GetMapping("{page}/{limit}")
public R pageList(
    @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){

    Page<Teacher> pageParam = new Page<>(page, limit);

    teacherService.page(pageParam, null);
    List<Teacher> records = pageParam.getRecords();
    long total = pageParam.getTotal();

    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

1、创建查询对象

创建com.guli.edu.query包，创建TeacherQuery.java查询对象

package com.guli.edu.query;

@ApiModel(value = "Teacher查询对象", description = "讲师查询对象封装")
@Data
public class TeacherQuery implements Serializable {

    private static final long serialVersionUID = 1L;

    @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

接口

package com.guli.edu.service;
public interface TeacherService extends IService<Teacher> {

    void pageQuery(Page<Teacher> pageParam, TeacherQuery teacherQuery);
}

实现

package com.guli.edu.service.impl;

@Service
public class TeacherServiceImpl extends ServiceImpl<TeacherMapper, Teacher> implements TeacherService {

    @Override
    public void pageQuery(Page<Teacher> pageParam, TeacherQuery teacherQuery) {

        QueryWrapper<Teacher> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByAsc("sort");

        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

TeacherAdminController中修改 pageList方法：
增加参数TeacherQuery teacherQuery，非必选

@ApiOperation(value = "分页讲师列表")
@GetMapping("{page}/{limit}")
public R pageQuery(
    @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){

    Page<Teacher> pageParam = new Page<>(page, limit);

    teacherService.pageQuery(pageParam, teacherQuery);
    List<Teacher> records = pageParam.getRecords();
    long total = pageParam.getTotal();

    return  R.ok().data("total", total).data("rows", records);
}

4、Swagger中测试