ios - Check if core data attributes, contains value before adding new one -


i'd check whether category name i'm create exists or not, in core data store.

if, exists, should display alert view , not create it. if doesn't exist, can carry on creation of new category.

 func createcategory() {             let entity = nsentitydescription.entityforname("category", inmanagedobjectcontext: context!)             let categoryentity = category(entity: entity!, insertintomanagedobjectcontext: context)             let index = pickerview.selectedrowincomponent(0)             let color = categorycolor[index]             let fetchrequest = nsfetchrequest(entityname: "category")                 fetchrequest.fetchlimit = 1             let predicate = nspredicate(format: "name = %@", name.text)             let fetchresults = context!.executefetchrequest(fetchrequest, error: &error) as? [category]              if let results = fetchresults {                 var requiredcategory : category                 if (results.count > 0) {                     requiredcategory = results[0] category                 } else {                     requiredcategory = category(entity: categoryentity, insertintomanagedobjectcontext: context!)                     requiredcategory.name = name.text                     // set other properties category necessary                 }                 category?.name = requiredcategory                 category!.descript = descriptionfield.text                 category!.color = color                 println(category!.name)                 context?.save(nil)             name.text = ""             descriptionfield.text = ""             }         }

you should create fetchrequest , execute before create categoryentity. then, check results.count. if count > 0 have 1 , should display alert. if isn't can create categoryentity, configure , save it.

note may want use =[cd] in predicate avoid multiple categories same name different capitalisation.


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