lambdaQueryWrapper多条件嵌套查询方式

目录

• lambdaQueryWrapper多条件嵌套查询
• 表结构如下
• 下面是根据条件生成的SQL语句
• LambdaQueryWrapper 常用条件

lambdaQueryWrapper多条件嵌套查询

需求：根据条件获取一段时期内按照年份和周存储的数据

表结构如下

/**
     * @param pageNum     当前页
     * @param pageSize    每页条数
     * @param moduleName  产品
     * @param userNetType 运营商
     * @param cityName    城市名称
     * @param beginTime   开始周的任意一天日期（例如：2019-12-20）
     * @param endTime     结束周的任意一天日期（例如：2020-01-20）
     * @param keyWord     查询条件（专题英文名或者中文名）
     * @return
     */
        //开始年份
        String beginYear = null;
        //结束年份
        String endYear = null;
        //开始周数
        String beginWeek = null;
        //结束周数
        String endWeek = null;
        /*这部分内容忽略，调用了其他的方法，
         反正就是为了获取开始日期所在的年份、周数以及结束日期所在的年份、周数*/
        if (StringUtils.isBlank(beginTime) || StringUtils.isBlank(endTime)) {
            DateTime dateTime = DateUtil.lastWeek();
            //格式化日期，结果：yyyyMMdd
            beginTime = DateUtil.formatDate(dateTime);
            beginYear = TimeUtils.getDateOfYearWeek(beginTime).get("year");
            endYear = beginYear;
            beginWeek = TimeUtils.getDateOfYearWeek(beginTime).get("week");
            endWeek = beginWeek;
        } else {
            beginYear = TimeUtils.getDateOfYearWeek(beginTime).get("year");
            endYear = TimeUtils.getDateOfYearWeek(endTime).get("year");
            beginWeek = TimeUtils.getDateOfYearWeek(beginTime).get("week");
            endWeek = TimeUtils.getDateOfYearWeek(endTime).get("week");
        }
        Page<DwSubjectDataInfoWw> page = new Page<>(pageNum, pageSize);
        LambdaQueryWrapper<DwSubjectDataInfoWw> queryWrapper = Wrappers.<DwSubjectDataInfoWw>lambdaQuery();
        if (beginYear.equals(endYear)) {
            queryWrapper.eq(DwSubjectDataInfoWw::getYear, beginYear);
            queryWrapper.between(DwSubjectDataInfoWw::getWeek, beginWeek, endWeek);
        } else {
            //因为Java8 Lambda表达式中最终变量问题，重新赋值一个参数解决
            String year1 = beginYear;
            String year2 = endYear;
            String week1 = beginWeek;
            String week2 = endWeek;
            queryWrapper.and(wrapper -> wrapper.and(wrapper1 -> wrapper1.eq(DwSubjectDataInfoWw::getYear, year1).ge(DwSubjectDataInfoWw::getWeek, week1))
                    .or(wrapper2 -> wrapper2.eq(DwSubjectDataInfoWw::getYear, year2).le(DwSubjectDataInfoWw::getWeek, week2)));
        }
        queryWrapper.orderByDesc(DwSubjectDataInfoWw::getYear);
        queryWrapper.orderByDesc(DwSubjectDataInfoWw::getWeek);
        if (StrUtil.isNotEmpty(cityName)) {
            queryWrapper.eq(DwSubjectDataInfoWw::getCityName, cityName);
        }
        if (StrUtil.isNotEmpty(userNetType)) {
            queryWrapper.eq(DwSubjectDataInfoWw::getUserNetType, userNetType);
        }
        if (StrUtil.isNotEmpty(moduleName)) {
            queryWrapper.eq(DwSubjectDataInfoWw::getModuleName, moduleName);
        }
        //搜索条件可以是专题中文名或英文名
        if (StrUtil.isNotEmpty(keyWord)) {
            queryWrapper.and(wrapper -> wrapper.like(DwSubjectDataInfoWw::getSubjectCname, keyWord).or().like(DwSubjectDataInfoWw::getSubjectEname, keyWord));
        }
        try {
            Page<DwSubjectDataInfoWw> list = dwSubjectDataInfoWwService.page(page, queryWrapper);
            return AjaxResult.success(list);
        } catch (Exception e) {
            logger.error("获取分周专题数据列表错误,错误信息为:", e);
            return AjaxResult.error();
        }

下面是根据条件生成的SQL语句

WHERE
    (
        (
            (year = ? AND week >= ?)
            OR (year = ? AND week <= ?)
        )
        AND city_name = ?
        AND user_net_type = ?
        AND module_name = ?
        AND (
            subject_cname LIKE ?
            OR subject_ename LIKE ?
        )
    )
ORDER BY
    year DESC,
    week DESC

LambdaQueryWrapper 常用条件

以上为个人经验，希望能给大家一个参考，也希望大家多多支持我们。