ios - Core Data:Fetch rlelationships or Fetch Main Entity -


i have entity a has to-many relationships entity b.

                   entity -->> entity b

i need refer count of to-many relationship, @ more 1 screen. further, can remove , add reference entity b entity a multiple times.

now, question : best way refer relationship count?

what observed:?

1] can make count attribute in entity a , increment/decrement according relationship count , fetch attribute on screens need.

2] can count count property of nsset(of relationships), way not have fetch entitya. can do,

      nsset *set =    entitya.entitiesb;       nsinteger count = set.count;

this way fetch happens not have create fetch request again , again entitya.

appreciate help.

you don't have fetch anything, can create fetch request suitable predicate , use countforfetchrequest:error: count. create fetch request template (setfetchrequesttemplate:forname:) , use fetchrequestfromtemplatewithname:substitutionvariables: when need use it.


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