我从iphone开始并且面临核心数据问题。核心数据问题
我有一个模型收集几个实体,如员工,项目,项目类型等在启动时,我创建了我通过核心数据框架仍然存在几个实体。没问题。
的问题提出时,我想显示的基础用户UIToolbar
内选择一个选项卡上的项目清单。我已经设置的参数显示(-com.apple.CoreData.SQLDebug 1
)发布的每一个SQL请求,什么是真正尴尬的是,在控制台中显示的查询给我的时候,通过源码而是从核心数据访问在我身边的分贝我的结果,不,0行返回...
任何人都遇到了类似的问题?
这里是用于检索的项目的列表的代码:
NSArray* retVal = nil;
NSError *error = nil;
NSManagedObjectContext *moc = "context retrieved";
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Project" inManagedObjectContext:moc];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:entityDescription];
retVal = [moc executeFetchRequest:request error:&error];
NSLog(@"Project type: %@", [theProjType valueForKey:@"projectTypeName"]);
NSLog(@"Employee number: %@", [theEmployee valueForKey:@"employeeNumber"]);
NSPredicate *predicate = [NSPredicate predicateWithFormat: @"ANY myEmployees.employeeNumber = %d AND myProjectType.projectTypeName = %d", [theEmployee valueForKey:@"employeeNumber"], [theProjType valueForKey:@"projectTypeName"]];
[request setPredicate:predicate];
retVal = [moc executeFetchRequest:request error:&error];
此代码生成此SQL请求(在源码分贝启动时返回结果):
SELECT DISTINCT 0, t0.Z_PK, t0.Z_OPT, t0.ZPROJECTNUMBER, t0.ZISEDITABLE, t0.ZPROJECTNAME, t0.ZISDELETABLE, t0.ZPROJECTEND, t0.ZPROJECTID, t0.ZPROJECTSTART, t0.ZCUSTOMERORDERNR, t0.ZMYCUSTOMER, t0.ZMYCOSTCENTRE, t0.ZMYPROJECTTYPE, t0.ZMYTRAVELTIMES FROM ZPROJECT t0 JOIN Z_4MYPROJECTS t1 ON t0.Z_PK = t1.Z_10MYPROJECTS1 JOIN ZEMPLOYEE t2 ON t1.Z_4MYEMPLOYEES = t2.Z_PK JOIN ZPROJECTTYPE t3 ON t0.ZMYPROJECTTYPE = t3.Z_PK WHERE (t2.ZEMPLOYEENUMBER = ? AND t3.ZPROJECTTYPENAME = ?)
这将有助于张贴在那里你建立NSFetchedResultsController代码并执行读取。 – Nimrod 2010-10-17 19:20:03
感谢Nimrod的建议,我为我的问题添加了一些代码。 – 2010-10-17 19:42:27