+[NSPredicate predicateWithFormat] 替换保留字

发布于 2024-12-22 02:55:39 字数 1078 浏览 1 评论 0原文

是否可以将保留字（特别是 OR 和 AND）替换为 predicateFormat？

我尝试过：

NSString *andOr = (isAnd ? @"AND" : @"OR");  // isAnd is a BOOL variable
NSPredicate *predicate = [NSPredicate predicateWithFormat:
                          @"firstName == %@ %K lastName == %@",
                          user.firstName, andOr, user.lastName];

但我得到：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: 'Unable to parse the format string "firstName == %@ %K lastName == %@"

我尝试了 %s （还有 %S）而不是 %K 但得到了相同的异常。

我现在的工作解决方案是单独创建 predicateFormat 。

NSString *predicateFormat = [NSString stringWithFormat:
                             @"firstName == %%@ %@ lastName == %%@", andOr]; 
NSPredicate *predicate = [NSPredicate predicateWithFormat:predicateFormat,
                          user.firstName, user.lastName];

但是，我想知道是否可以在不单独创建 predicateFormat 的情况下完成此操作。

原文

Is it possible to substitute reserved words, specifically OR and AND, into a predicateFormat?

I tried:

NSString *andOr = (isAnd ? @"AND" : @"OR");  // isAnd is a BOOL variable
NSPredicate *predicate = [NSPredicate predicateWithFormat:
                          @"firstName == %@ %K lastName == %@",
                          user.firstName, andOr, user.lastName];

But I got:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: 'Unable to parse the format string "firstName == %@ %K lastName == %@"

I tried %s (and also %S) instead of %K but got the same exception.

My working solution for now is to create the predicateFormat separately.

NSString *predicateFormat = [NSString stringWithFormat:
                             @"firstName == %%@ %@ lastName == %%@", andOr]; 
NSPredicate *predicate = [NSPredicate predicateWithFormat:predicateFormat,
                          user.firstName, user.lastName];

But, I was wondering if this could be done without creating predicateFormat separately.

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海拔太高太耀眼 2024-12-29 02:55:39

是的，它可以：

NSPredicate *firstName = [NSPredicate predicateWithFormat:@"firstName == %@", [user firstName]];
NSPredicate *lastName = [NSPredicate predicateWithFormat:@"lastName == %@", [user lastName]];
NSArray *subpredicates = [NSArray arrayWithObjects:firstName, lastName, nil];

NSPredicate *predicate = nil;
if (isAnd) {
  predicate = [NSCompoundPredicate andPredicateWithSubpredicates:subpredicates];
} else {
  predicate = [NSCompoundPredicate orPredicateWithSubpredicates:subpredicates];
}

Yep, it can:

NSPredicate *firstName = [NSPredicate predicateWithFormat:@"firstName == %@", [user firstName]];
NSPredicate *lastName = [NSPredicate predicateWithFormat:@"lastName == %@", [user lastName]];
NSArray *subpredicates = [NSArray arrayWithObjects:firstName, lastName, nil];

NSPredicate *predicate = nil;
if (isAnd) {
  predicate = [NSCompoundPredicate andPredicateWithSubpredicates:subpredicates];
} else {
  predicate = [NSCompoundPredicate orPredicateWithSubpredicates:subpredicates];
}

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别把无礼当个性 2024-12-29 02:55:39

使用搜索栏文本我正在过滤数据。

下面的代码很简单，不需要任何解释

NSString *predFormat=[NSString stringWithFormat:@"FirstName CONTAINS[c] '%@' OR LastName CONTAINS[c] '%@' OR Phone CONTAINS[c] '%@'" ,搜索值,搜索值,搜索值]; //LIKE

NSPredicate *predicate = [NSPredicate predicateWithFormat:predFormat];

NSArray *tempData = [数组filteredArrayUsingPredicate:谓词];

希望这对你有用..
快乐编码....

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