Databases
StackOverflow2013
Usersdbo
USJoshua Pokotilow
 

Note that there are some explanatory texts on larger screens.

plurals
  1. USJoshua Pokotilow
    primarykey
    data
    text
    plurals
    1. POHow does one architect an entity in Core Data with a generic relationship?
      singulars
      1. PTQuestion
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COI know this is an old post, but I feel it's worth adding: these methods *do* get called automatically when you try to save a managed object, and the error they set is also percolated back to the caller through the documented error-handling mechanism. Furthermore, it wouldn't make sense for CD to call validation methods when you set properties, since setters are void methods that don't take an NSError ref for a parameter. That having been said, I'll grant you that if you want to validate inputs in the GUI without saving, then it absolutely makes sense to call validateValue:forKey:error.
      singulars
      1. PO
      1. USJoshua Pokotilow
    2. CO@Caleb No, I mean that if you have 1 million owner entities spread out over 100 different tables, and each of those entities has a picture, and you have just 1 table for pictures (because you use inheritance for your Picture entity) then your picture table will contain 1 million rows -- 1 row for each picture.
      singulars
      1. PO
      1. USJoshua Pokotilow
    3. CO@Caleb That's actually what I'm doing; I misspoke when I said I was creating subentities for my owner entities. But the problem you mentioned in your original answer is still present -- that is, creating Picture subentities is scary from an under-the-hood perspective since one table will grow by 1 row for every inserted owner entity. So hypothetically, if you have 100 owner entity tables and each one has 10,000 rows, you'll wind up with a single Picture table with 1 million rows.
      singulars
      1. PO
      1. USJoshua Pokotilow
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload