Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>From your question and the comments I <strong>guess</strong> that you want</p> <pre><code>[NSPredicate predicateWithFormat:@"mode = 0 AND (ALL enrollments.mode = 0)"] </code></pre> <p><strong>UPDATE</strong></p> <p>It seems that the ALL aggregate does not work. It throws </p> <pre><code>'NSInvalidArgumentException', reason: 'Unsupported predicate (null)' </code></pre> <p>as @yunas noticed. This has also been noticed previously, e.g.</p> <ul> <li><a href="https://stackoverflow.com/questions/1164338/core-data-nspredicate-and-to-many-key">Core Data, NSPredicate and to-many key</a></li> <li><a href="https://stackoverflow.com/questions/5922139/crash-using-aggregate-operation-all-in-a-core-data-ios-application">Crash using Aggregate Operation: &quot;ALL&quot; in a Core Data iOS Application</a></li> </ul> <p>On the other hand, the ANY aggregate works just fine. So as a <strong>WORKAROUND</strong>, one can replace ALL with an equivalent ANY expression:</p> <pre><code>[NSPredicate predicateWithFormat:@"mode = 0 AND NOT(ANY enrollments.mode != 0)"]; </code></pre> <p>And this actually works (I have tested it)!</p> <p><strong>UPDATE 2</strong></p> <p>During the discussion it has become clear that yunas wants to display a table with one row for each group with mode=0, and within the table row display all enrollments of that group with mode=0.</p> <p><em>First solution (probably the better one):</em> Find all admissible groups first with the method given above. For each row (in <code>cellForRowAtIndexPath:</code>) filter the enrollments for that group and draw the cell.</p> <p><em>Second solution:</em> Fetch all enrollments and sort them by group. This requires only one fetch request, but the result is not so suitable as table view data source. The fetch request would look like this:</p> <pre><code>NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"Enrollment"]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"mode = 0 AND group.mode = 0"]; request.predicate = predicate; NSSortDescriptor *sort1 = [NSSortDescriptor sortDescriptorWithKey:@"group.name" ascending:YES]; NSSortDescriptor *sort2 = [NSSortDescriptor sortDescriptorWithKey:@"share" ascending:YES]; request.sortDescriptors = [NSArray arrayWithObjects:sort1, sort2, nil]; </code></pre>
    singulars
    1. This table or related slice is empty.
    1. PONSPredicate on nested object / NSSet to filter the result during NSFetchRequest
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCommunity
    1. USMartin R
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PONSPredicate on nested object / NSSet to filter the result during NSFetchRequest
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    1. COcan we do (ALL enrollments.mode = 0) ??? The problem I have is , I dont know how to access the nested objects attribute.
      singulars
      1. PO
      1. USyunas
    2. COI would not give this answer I were not fairly confident that it is correct. YOU should try now if it works. If it works: Fine, accept my answer. If not: Show your code and ask again.
      singulars
      1. PO
      1. USMartin R
    3. COYou could also have a look at the [Predicate Programming Guide](http://developer.apple.com/library/ios/#DOCUMENTATION/Cocoa/Conceptual/Predicates/predicates.html#//apple_ref/doc/uid/TP40001798-SW1). It has examples like "ALL children.age > 12" at the very beginning.
      singulars
      1. PO
      1. USMartin R
 

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