CODEWITHSUNDEEP
iosobjective-ccore-datansarraynspredicate
Sachin
Sachin

Reputation: 343

NSPredicate for finding only the first match

In Core Data, I have a field called UUID which is a unique id.

Now, I want to fetch a single specific UUID record. For that i need to use NSPredicate. But from what I know, the predicate would search the entire data store. For example suppose there are 10 records and I want to search for the UUID which has a value of 2. The predicate will continue the search after it's found 2 (taking extra CPU cycles).

I want to know if we can optimise this. How can I make the predicate stop searching once its found the first object.

Upvotes: 0

Views: 1269

Answers (1)

Wain
Wain

Reputation: 119031

In Core Data, use setFetchLimit: on the fetch request to limit the number of results. You can also add an index to the UUID attribute if you are going to be using it frequently.

If you want to run the predicate on an array instead and limit the hits you would need to iterate the array yourself (enumerateObjectsWithOptions:usingBlock:) and explicitly apply the predicate to each item (evaluateWithObject:). Then, when you find a match, use the BOOL *stop parameter of the block to end the iteration.

Upvotes: 2

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