constraints

问题 I'd like to affect m groups (m ~ 20) of students to n projects (n ~ 6). There is an additional constraint : I can only affect beetween p (p ~ 4) to q (q ~ 6) groups to each project. Each group has to order the projects from the one it likes most to the worst. I've read I could use the Hungarian algorithm if m = n and I should use the Ford-Fulkerson algorithm or the Edmonds–Karp algorithm in the general case. Could you please help me to discern what will the graph be in my case ? I guess nodes

问题 As can be seen below, my toolbar gets chopped off in the compact size: My UI consists of a ToolBar and a WebView. The constraints I tried don't work, although I did get them to turn blue. As you can see, my toolbar is pinned to the top, the left side, and the right side (I also set a constant height). How can I get my toolbar to display correctly in the compact size. Thanks. Edit1: Edit2: Here is what I did to get things to display correctly: I had to drag the edges of the WebView all the way

问题 In viewDidLoad func of my UIViewController I call print("\(UIScreen.main.bounds.size.width) \(collectionView.frame.width)") and it prints 320.0 375.0 How is it possible? UICollectionView should has the same width, mb smaller but definitely not bigger Settings of this view in storyboard: each constraint set as So I test it on iPhone SE Simulator but in Storyboard I have iPhone 8. But I believe it should not matter at all when I use autolayout (constraints to make size of my view match size of

问题 I'm new to Grails and obviously missing something out.. but what?! I created a DomainClass An with a String property category. In the constraints I defined, that this category should have multiple (list) values: class An { String category static constraints = { category nullable: true, inList:["do", "me", "a", "favour"] } } In the view it is shown as a multiple select box: <g:select name="category" from="${anInstance.constraints.category.inList}" value="${anInstance?.category}"

问题 I have a table called BFFs, that stores userID, and best friend's userID and I would like to restrict that table to have exactly 3 number of best friends for each different user. I mean if the table structre is: BFFs(userID, userID) and records are: (3286, 1212) (3286, 4545) (3286, 7878) And in that case, if user with ID 3286 should not be allowed to have a new record such as (3286, xyzt). I wrote this trigger but I'm not sure: CREATE TRIGGER BFFControl BEFORE INSERT ON BFFs FOR EACH ROW

问题 I have the following two classes, one ReqCandAssociation can have many Comments and it is mapped like so. I need to figure out a way that when I delete a ReqCandAssociation it deletes all of its associated comments. Thanks @Entity @Table(name = "candidate_jobReq") public class ReqCandAssociation implements Serializable { @Id private Integer candidateId; @Id private Integer jobId; @Column(name = "reqStatus") private String reqStatus; @ManyToOne @PrimaryKeyJoinColumn(name="candidateId",

问题 all my view controllers and constraints are fine in iOS 11 and above but in iOS 10 and below a space created in all pages like the pictures below : I tried even a simple web view in a viewcontroller with four constraints to safe area but I've got the same result.(good view in iOS 11 and above and a space to top in iOS 10 and below. and another strange thing is that some of my apps now have this problem and some don't :| . what should I do? 回答1: Can you try this? if #available(iOS 11.0, *) {

问题 I got three collectionViews in my application. Now I finished it as far as I wanted it to complete. The only problem which I have for several days now are the constraints. I don't know how to explain it in words so I added two pictures of the problem to the question I hope it's understandable. What I currently have: What I want: 回答1: Use UICollectionViewDelegateFlowLayout delegate method to archive this. func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout:

问题 I'm working on SQL Server and am trying to drop a column. The table schema is as below: CREATE TABLE [dbo].[XYZ]( [ID] [int] NOT NULL, [DSC] [varchar](255) NULL, [LOWER_LIMIT] [int] NOT NULL, [UPPER_LIMIT] [int] NOT NULL, CONSTRAINT [XP_XYZ] PRIMARY KEY CLUSTERED ( [ID] ASC ) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO When I attempt to drop the column : ALTER

问题 It's easier with an example. I have two tables: Books and Chapters. Both have Title and Id columns. Chapters also has a Book column which is a foreign key to Books.Id. Books.Title is unique (I don't want two books with the same title). Now my problem is defining Chapter.Title uniqueness. I want it to be unique as long as Books.Id is the same. So that one book may not have two chapters with the same title but two different books may have the same title in a chapter. Is this possible on SQL