I have promoted mySQL-based database views to Entities. All works fine except that I cannot add standard fields to these Entities other than URLs.
So, only when right-clicking on an Entity that was created by promoting a database view, and then choosing 'New Standard Field...' the Window shown in the attached image pops up, instead of the normal New Standard Field window, allowing to choose the type of field etc.
Is this behavior to be expected for Entities that originate from Views, i.e. is it not possible to add Fields? I was able to add Calculated Fields. This is in IJC 188.8.131.52.
This is expected behaviour.
In case of database views, it is not possible to add new fields as the DB view does not contain any "real data" from the DB point of view (it is more of an abstraction than a real DB table). Any IJC entity based on a DB view will be as "read only" because of that.
Being able to add url fields is peculiar to me. I will check this. But in general can not add any standard field into an entity based on a DB view.
The exception to this behaviour would be Oracle's Materialised view, which works differently and in fact "pulls" data from the original DB table and data is stored in 2 places at once in the DB - the original DB table and the materialised view, compared to ordinary DB view, where the data is stored only in the original table. MySQL does not have a Materialised View possibility.
Regarding the calculated fields, those are calculated by JChem layer and their definitions are stored in IJC metadata, which are separated from your DB tables or views, therefore you can add them into the view based entity.
I hope this helps
Wishing all the best
All right, I suspected something like this. No problem, and thanks for explaining!