objective-c – 对一个查询字符串进行多重比较的NSPredicate

我想知道是否有一种方法可以简化nspredicate,它可以为多个比较目标提供单个查询字符串.我正在为同一个查询字符串搜索核心数据实体的多个属性.我当前的查询看起来像这样……

[nspredicate predicateWithFormat:@"(attributeA contains[cd] %@) OR (attributeB contains[cd] %@) OR (attributeC contains[cd] %@)",searchString,searchString];

请注意,这非常有效,但看起来确实有点不雅观.特别是searchString,searchString部分.关于如何简化这一点的任何提示都会很棒！

谢谢！

解决方法

您可以将NSCompoundPredicate用于您的OR&和这样的操作.

Obj-C – 或

// OR Condition //

nspredicate *predicate1 = [nspredicate predicateWithFormat:@"X == 1"];
nspredicate *predicate2 = [nspredicate predicateWithFormat:@"X == 2"];
nspredicate *predicate = [NSCompoundPredicate orPredicateWithSubpredicates:@[predicate1,predicate2]];

Obj-C – AND

nspredicate *predicate1 = [nspredicate predicateWithFormat:@"X == 1"];
nspredicate *predicate2 = [nspredicate predicateWithFormat:@"X == 2"];
nspredicate *predicate = [NSCompoundPredicate andPredicateWithSubpredicates:@[predicate1,predicate2]];

斯威夫特 – 或者

let predicate1:nspredicate = nspredicate(format: "X == 1")
let predicate2:nspredicate = nspredicate(format: "Y == 2")
let predicate:nspredicate  = NSCompoundPredicate(orPredicateWithSubpredicates: [predicate1,predicate2] )

斯威夫特 – 和

let predicate1:nspredicate = nspredicate(format: "X == 1")
let predicate2:nspredicate = nspredicate(format: "Y == 2")
let predicate:nspredicate  = NSCompoundPredicate(andPredicateWithSubpredicates: [predicate1,predicate2] )

斯威夫特3 – 或

let predicate1 = nspredicate(format: "X == 1")
    let predicate2 = nspredicate(format: "Y == 2")
    let predicateCompound = NSCompoundPredicate.init(type: .or,subpredicates: [predicate1,predicate2])

斯威夫特3 – 和

let predicate1 = nspredicate(format: "X == 1")
    let predicate2 = nspredicate(format: "Y == 2")
    let predicateCompound = NSCompoundPredicate.init(type: .and,predicate2])