预期的结果没有得到

Question

我有三个表格，显示在此演示中： sql fiddle demo

这些是预期的条件和结果

您可以在此处查看演示中的activity_id和region_id，并将unit_id设为MEASUREMENT_UNIT_ID。

到目前为止我尝试了什么：

select t.entity_id, t.parent_id, t.length,gu.measurement_unit_id
    from tree t
    left join product_autoselect_units u
    on t.parent_id = u.region_id
    or t.parent_id = u.activity_id
    or t.entity_id IN (ACtivity_id)
    left join units gu
    on u.id = gu.unit_id
    WHERE t.entity_id IN (Region_id)

查询显示演示正在获得此条件和结果

所以这里的activity_id = 5753和region_id = 10没有得到预期的结果。我想要空值作为结果......你可以在演示中查看。

非常感谢帮助。

Answer 1

i have tried you query on given link in your post

try to put your id for time being like in below query and see the result
select t.entity_id, t.parent_id, t.length,gu.measurement_unit_id
    from tree t
    left join product_autoselect_units u
    on t.parent_id = u.region_id
    or t.parent_id = u.activity_id
    or t.entity_id IN (ACtivity_id)
    left join units gu
    on u.id = gu.unit_id
where t.entity_id in (5742,5753)
  ##WHERE t.entity_id IN (Region_id)