relationship

问题 I have table like this below where it save all data with reference id :- ID Name RefID A AAAA null B BBBB A C CCCC B D DDDD C E EEEE D F FFFF E Firstly I need some query where I can scan which are the top three reference id level only and show up. --- Example: When D added below C --- GLevel ID RefID No Start A (3) Level(1) B (A) (2) Level(2) C (B) (1) Level(3) D (C) Result (Down To Top): A,B and C are top three reference id for D Result (Top to Down): A have B,C and D as child based refid

问题 I'm starting to learn and practice some CoreData, with no programming experience. After searching in Web, looking for Apple samples and reading some books, I´m still stucked in one point. I have two entities (Expenses and Month) with reciprocal relationships called "monthsOfExpense" and "expensesOfmonth" and I'm showing in a tableView the expenses of a single month. My problem is to insert new expenses and save them: I've a view to insert new expenses where the user can insert the name of

问题 I'm fairly new to coredata and have been stuck on an issue. Any assistance will be greatly appreciated. Information: I have a core data app with to entities; List and Task. List and Task have a one-to-many relationship. Task.h @class List; @interface Task : NSManagedObject @property (nonatomic, retain) NSString * task; @property (nonatomic, retain) NSString * note; @property (nonatomic, retain) List *list; @end List.h @class Task; @interface List : NSManagedObject @property (nonatomic, retain

问题 I'm new to Laravel. Currently trying to use eloquent in one of my application. I've 3 database tables.. trips, trips_album, album_images. Table column are as follows.. trips - id(auto increment), trip_title, about_place, created_by trips_album - id(auto_increment), trips_id(pointing to 'id' of trip table), album_status album_images - album_id(pointing to 'id' of trip_album table), img_name So, now i want all album images of trips, which belong to any particular user. How can i do this by

问题 How can I represent an Album entity which can be vinyl and/or cd and/or tape. I assume those can't be declared as subtypes of the Album entity as there would be no way the album could be all of them. Should it be a multivalue attribute of the Album entity? Also each type vinyl, cd, tape have different attributes (eg. vinyl might have colour, cd might have an associated video clip etc.) And for an Artist entity how could I make a solo artist and a group artist? At the minute I have an Artist

问题 The bounty expires in 2 days . Answers to this question are eligible for a +50 reputation bounty. User1973 wants to draw more attention to this question. I have an automation script in Maximo 7.6.1.1 that updates custom fields in the WORKORDER table. I want to execute the automation script when the LatitudeY and LongitudeX fields (in the WOSERVICEADDRESS table) are edited by users. For performance reasons, I would prefer to only call the script when necessary (when the LatitudeY and

问题 The question i have is in regards to a Core Data one-to-many relationship as of right now i have my app being able to let the user input employee information and saving to core data , then updating the employee table view. The problem i face is the relationship between the employee and delivery. Im currently trying to display a specific employees deliveries when clicking on an employee in the employee table view. After selecting an employee from the employee tableView i want it to segue to

问题 Because my app is multi-threaded I use two NSManagedObjectContexts. The main context, that runs in the main thread and another context that only runs in a separate thread. I have created a small test app. It has two Core Data Entities. Parent and Child. Parent has a one-to-many relationship to Child. Child has a 1-1 relationship to Parent. In one test method (that runs in a separate thread) I get a Parent instance, that has been created during a run time before. So it's in the main context. I

问题 Working with Entity Framework 6, I have a Person class... public class Person { public int ID { get; set; } public string Name { get; set; } public virtual ICollection<Relationship> Relationships { get; set; } } and a Relationship Class public class Relationship { public int ID { get; set; } public RelationshipType DependencyType { get; set; } [ForeignKey("Person")] public int PersonID { get; set; } public virtual Person Person { get; set; } public virtual ICollection<Person> RelatedPersons {

问题 With the following entity relationship structure I'm struggling to figure out if the relationship between the LOAN and ITEM entities is valid? The weak entity of LOAN uses a partial key of 'loan_dateLeant' and the primary keys from CUSTOMER and ITEM to form LOANs primary key. However LOAN has a 'one to many' relationship with ITEM as a loan can consist of more than one item. But surely this means that if more than one item is loaned, then the loan record will have two item_id values for part