constraints

问题 I am making a view for conversation between two people. I have used UICollectionView with custom cell and using a flag based upon which I decide whether the message should be aligned towards left or right. The constraints work correctly if I use only a single direction of alignment, it even works correctly with condition based alignment unless number of messages in UICollectionView is less than four. So I know that constraints are not wrong. But as soon as I add the fourth message the

问题 In my current project, I decided to create only one translatable File entity and reuse it for all image/document properties I have. For the translations, I uses Knp Doctrine Behaviors Translatable. So here is the code. The file class: class File { use ORMBehaviors\Translatable\Translatable; /** * @var integer * * @ORM\Column(name="id", type="integer") * @ORM\Id * @ORM\GeneratedValue(strategy="AUTO") */ protected $id; public function __toString() { return (string)$this->id; } /** * Get id * *

问题 Example scenario. In a flight schedule system, there are a pilot table which refers to a plane_type table indicating the planes the pilot is able to fly (assuming that is a many-to-one relation). There are also a plane table and it refers to the plane_type table to indicate the plane's type (also many-to-one relation). Now there is an associative table flight_plan which assigns a pilot to a plane for a given flight. How do I make sure the pilot 's qualification do match the plane 's type for

问题 I'm trying to add an image inside the navigation constroller and center it. So I do have an imageView and a UINavigationBar and I want to add the image view to that navigation bar and center it horizontally. The UINavigationBar comes from the UINavigationController . I keep getting the following error: The view hierarchy is not prepared for the constraint: When added to a view, the constraint's items must be descendants of that view (or the view itself). This will crash if the constraint

问题 Suppose I have a table: CREATE TABLE `ml_vendor_refs` ( `id` int(11) NOT NULL AUTO_INCREMENT, `ml_id` int(11) NOT NULL, `ven_id` int(11) NOT NULL, `designator` int(4) NOT NULL, `telco` tinyint(1) NOT NULL DEFAULT '0', PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=5 DEFAULT CHARSET=latin1 As you can see, "id" is primary and AI. However, I want to be able to add several rows of 'designator' that my not duplicate based on the parent of 'ml_id' and 'telco'. For example: "id" "ml_id" "ven_id"

问题 I have created the following 3 tables using the following code. CREATE TABLE BUILDING( BUILDINGNO CHAR(2), BUILDINGWING VARCHAR2(15), BUILDINGLANE VARCHAR2(15), CONSTRAINT BUILDING_PK PRIMARY KEY(BUILDINGNO)); CREATE TABLE ROOM( BUILDINGNO CHAR(2), ROOMNO CHAR(2), ROOMCAPACITY NUMBER(3), CONSTRAINT ROOM_PK PRIMARY KEY(BUILDINGNO,ROOMNO), CONSTRAINT ROOM_FK1 FOREIGN KEY(BUILDINGNO) REFERENCES BUILDING(BUILDINGNO)); CREATE TABLE SPEAKER( SPEAKERID CHAR(2), SPEAKERNAME VARCHAR2(20),

问题 Question: Is there any way that I could set IBOutlet properties programmatically and in an automated way (i.e. without hard-coding the properties to be set)? Maybe there is some "IBOutlet setting" routine that I could intercept with my own specialized code? Background: The problem leading to the question above originates from the fact that "IBOutleted" size constraints (width and height) are not being set when running the following method (it's a method for replacing a "placeholder" view from

问题 I'm developing a SOAP application using JAX-WS and JAXB. I'd like to specify a pattern constraint for one of the fields (a Dutch postcode, \d{4}[A-Z]{2} ). That's very easy to do using xsd:pattern , but I can't find the equivalent JAXB annotation. How do I achieve this? 回答1: You can't. The idea is to use JAXB annotations in combination with runtime validation against the schema, using javax.xml.validation.Schema , which can be plugged into the Marshaller and Unmarshaller . 来源： https:/

问题 I want to implement a kind of xor constraint on foreign keys in mysql 5.1 There is this table, let's say Entity which can refer to two different kinds of valuesets represented by Tables ValsA and ValsB. Now I would like to implement a constraint wich makes sure that exactly one of those two is mapped, and the other one isn't. In Oracle you could use something like CHECK (NVL2(FK_A,1,0)+NVL2(FK_B,1,0)=1)); but as far as I understand it MySQL does not really support CHECK Constraints (yet). Any

问题 I have a Spring webapplication that uses hibernate validator for validation. I have constraint annotations that are located in a different project. I need to have validators for these constraints in my spring project because I need some services to perform validation. So the situation is: I cannot place my constraint validators in @Constraint(validatedBy = MyConstraintValidator.class) because the validator is in a different project, I cannot add a dependency because that would create a cyclic