Hi Dmitri,
if you have a full schema defined you can query it with
select customFields from (
select expand(classes) from metadata:schema
) where name="YourClassName"
and
select customFields from (
select expand(properties) from (
select expand(classes) from metadata:schema
) where name="YourClassName"
) where name="PropertyName"
If you have partial or no schema defined, you can use FIND REFERENCES
command
http://orientdb.com/docs/last/SQL-Find-References.html
Just take into consideration that it scans the whole database, so it's
very inefficient
Thanks
Luigi
2015-10-30 22:15 GMT+01:00 <[email protected]>:
> Luigi - Thank you. I understand the tradeoff.
>
> OK, I have to manage this manually. What is the best way?
>
> Is there any way to query the schema and find out which objects have
> fields that reference a particular class? (so that I can NULL them and then
> remove the class)
>
> Regarding using Graph type: yes, maybe. But I really like the simple dot
> notation as it works with LINKs. I think it is very elegant. (I take my
> syntactic sugar wherever I find it)
>
>
> On Friday, October 30, 2015 at 3:55:07 AM UTC-4, Luigi Dell'Aquila wrote:
>>
>> Hi Dmitri,
>>
>> Document layer does not manage link consistency, just for a matter of
>> performance, but Graph layer does (eg. it removes dangling edges when you
>> delete a vertex). My advice is to use edges instead of links, it will also
>> give you another advantage, that is having bi-directional traversal of
>> pointers
>>
>> Thanks
>>
>> Luigi
>>
>>
>> 2015-10-30 2:47 GMT+01:00 <[email protected]>:
>>
>>> Hello,
>>>
>>> This question was asked in 2013, and Luca's reply was as follows:
>>>
>>> On Monday, May 20, 2013 at 6:20:24 PM UTC-4, Lvc@ wrote:If you remove a
>>>> document is your responsibility to clean all the references.
>>>>
>>>
>>> Does this answer still hold? If yes, how can I find all the references
>>> to a class that is about to be deleted? (or what is the recommended way of
>>> otherwise dealing with this issue?)
>>>
>>> I am using 2.1.2 (trying it out) and I was quite amazed to find that the
>>> database allowed me to drop the referenced class and kept the RID of the
>>> referenced object (dangling pointer, basically).
>>>
>>> The scary thing was that once I created (and populated) another class,
>>> the cluster id was reused, and the RID happily pointed to a new, entirely
>>> unrelated object.
>>>
>>> Thanks!
>>> Dmitri
>>>
>>>
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