fetchRequestFromTemplateWithName变量 [英] fetchRequestFromTemplateWithName variables

问题描述

我使用Xcode 4.2.1并尝试使用一个变量。我理解在xcode 4，你需要设置变量 $ variable 。我在Xcode中为我的获取请求变量为 $ currDate

I'm using Xcode 4.2.1 and trying to use a variable. I understand in xcode 4 you need to set the variable with $variable. I have in Xcode for my fetch request the variable as $currDate

，我的代码为

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
    [dateFormatter setDateFormat:@"YYYYMMdd"];
    NSDate *currDate = [NSDate date];
    NSString *currDateString = [dateFormatter stringFromDate:currDate];
    NSError *error;
    NSFetchRequest *fetchRequest = [[[DataManager sharedInstance] objectModel] fetchRequestFromTemplateWithName:@"fetchAppointmentsByDate" substitutionVariables:[NSDictionary dictionaryWithObject:currDateString forKey:@"currDate"]];
     NSLog(@"Fetch Request: %@", fetchRequest);
    NSArray *appts = [[[DataManager sharedInstance] managedObjectContext] executeFetchRequest:fetchRequest error:&error];
    NSLog(@"Fetch Request Results: %i %@ - %@", [appts count], appts, error);

但是它不返回任何结果，我知道结果。

However it is not returning ANY results and I know results are there.

日志：

2012-02-24 14:16:29.332 MyApp[2687:fb03] Fetch Request: <NSFetchRequest: 0xb7641c0> (entity: Appointments; predicate: (date == "$currDate"); sortDescriptors: ((null)); type: NSManagedObjectResultType; )
2012-02-24 14:16:29.334 MyApp[2687:fb03] Fetch Request Results: 0 (
) - (null)

我在这里做了一些工作，我在上面的Xcode的屏幕截图中找到了 c $ c> $ currDate 到 20120224 < xcode中的获取请求模板的变量是否错误4.2？

Am I doing the variable thing for fetch request templates wrong in xcode 4.2?

UPDATE 1：

这个？

推荐答案

单击属性名称，在您的情况下 date 并在弹出菜单中选择表达式。

Click on the attribute name which in your case is date and select "Expression" in the popup menu. That allows you to input the variables.

在您的情况下，将Expression字段设置为： date == $ currDate

In your case set the Expression field to: date == $currDate

这对我有用。

编辑：为了更像Xcode 3树型的情况，下拉选项键，您可以以相同的方式添加子谓词。当您按住选项键时，+号会变成...：

To get more like Xcode 3 tree type of situation, you hold down the option key, you can add a sub-predicates in the same way. The '+' sign changes to the "..." when you hold the option key down like so:

您可以实现相同的结果。

You can achieve the same result that way.

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