mybatisplus 复杂查询，组合or，lambdaQuery

最新推荐文章于 2025-04-27 13:13:54 发布

最差的一届

最新推荐文章于 2025-04-27 13:13:54 发布

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分类专栏： java 文章标签： java mybatisplus lambda

本文链接：https://blog.youkuaiyun.com/weixin_43159092/article/details/121292482

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查询需求

多个and组合成一个组合条件，多个组合条件之间用或连接（or）.
例如：

SELECT basic_rule_snapshot_id FROM alarm_info WHERE (
status = ? AND (
(basic_rule_snapshot_id = ? AND industry_device_id = ?) OR
(basic_rule_snapshot_id = ? AND industry_device_id = ?) OR
(basic_rule_snapshot_id = ? AND industry_device_id = ?)
)
)

lambdaQuery

 wrapper.select(AlarmInfo::getBasicRuleSnapshotId).eq(AlarmInfo::getStatus, AlarmStateEnum.RUNNING.getState());
        wrapper.and(w->{
                query.getIndustryDeviceSnapshotList().forEach(item->{
                    w.and(t->{
                        t.eq(AlarmInfo::getBasicRuleSnapshotId,item.getBasicRuleSnapshotId())
                                .eq(AlarmInfo::getIndustryDeviceId,item.getIndustryDeviceId());
                        w.or();
                    });
                });
        });

错误写法

容易出错的地方是or()的位置

List<String> serviceIds = query.getServiceIds();
if (CollUtil.isNotEmpty(serviceIds)) {
    wrapper.and(q ->
            serviceIds.forEach(serviceId -> {
                if (StrUtil.isBlank(serviceId) || !serviceId.contains("@")) {
                    return;
                }
                q.and(x->
                        x.eq(AlarmInfo::getSourceFrom, serviceId.split("@")[0])
                        .eq(AlarmInfo::getPointLongCode, serviceId.split("@")[1])).or();
                        //此处or()无用，lambda自行体会。
            })
    );
}

导致sql的or被and替代。

SELECT basic_rule_snapshot_id FROM alarm_info WHERE (status = ? AND ((basic_rule_snapshot_id = ? AND industry_device_id = ?) AND(basic_rule_snapshot_id = ? AND industry_device_id = ?) AND(basic_rule_snapshot_id = ? AND industry_device_id = ?)))