relation

问题 When I try to use a simple Criteria on a property with a different columnname in Many-To-Many-Relation, Doctrine uses the propertyname as the field and not the columnname. Person ORM Definition ... manyToMany: attributes: targetEntity: Attributes cascade: ['persist'] joinTable: name: person_attribute joinColumns: person_id: referencedColumnName: id inverseJoinColumns: attribute_id: referencedColumnName: id ... Attribute ORM Definition with differing columnname ... name: type: string nullable:

问题 I have a model named Post (blog post) and a model named Category . Each post belongs_to a category. Each category has an attribute named retainer that specifies the amount of time before a post "expires", so for example movies_category.retainer = 30.days What I'm trying to do is create a scope for Post that finds all of the posts which are "expired". So for example, assuming I were to hardcode the value of 30.days and it were to apply to all categories (therefore all posts), the scope would

问题 I am working on another question here and it asks for the candidate keys and the superkeys. I believe I have the correct candidate keys, but if someone could verify that would be great. I am also just having trouble finding superkeys. I don't know if there is a general formula to find them or whatnot. Here is the question: Relation Schema: U(A,B,C,D) FD's: A-->B B-->C C-->D D-->A I found the Candidate keys to be: {A},{B},{C},{D}. If someone could verify if this is correct, I would greatly

问题 I try to create a polymorphic association, what is common in Rails but unfortunately not in Yii2. As part of the implementation I need to define the relation: public function getImages() { return $this->hasMany(RecipeImage::className(), ['imageable_id' => 'id', 'imageable_type' => 'Person']); } But this doesn't work, because 'Person' is treated as an attribute of the current model, but it is a constant (class name for the polymorphic association). If I try to use 'andWhere' it adds the

问题 I am recently working on using nltk to extract relation from text. so i build a sample text:" Tom is the cofounder of Microsoft." and using following program to test and return nothing. I cannot figure out why. I'm using NLTK version: 3.2.1, python version: 3.5.2. Here is my code: import re import nltk from nltk.sem.relextract import extract_rels, rtuple from nltk.tokenize import sent_tokenize, word_tokenize def test(): with open('sample.txt', 'r') as f: sample = f.read() # "Tom is the

问题 For my application I need to represent simultaneously (on the same graph) two relations: one is simmetric, the other is not. Targets: Ideally the two relation should result in edges having different colors; For the symmetric relation I would like not to have double-edges; Is there a way of doing this with dot ? 回答1: digraph { A; B; C subgraph Rel1 { edge [dir=none, color=red] A -> B -> C -> A } subgraph Rel2 { edge [color=blue] B -> C C -> A } } 来源： https://stackoverflow.com/questions

问题 I am developing an iPhone application that has support for video play. I am using MPMoviePlayerController with custom controls for playing the video. For this purpose I have set control style of MPMoviePlayerController to MPMovieControlStyleNone. I would like to support AirPlay feature for the video being played. As per the documentation, we have to set the 'allowsAirPlay' property of MPMoviePlayerController to YES to enable AirPlay feature. How can I display the AirPlay button on my player

问题 My table Website Website_Name//column name Google Facebook Twitter Orkut Frype Skype Yahoo Wikipedia I i use utf8_bin collation then my query to search wikipedia in Website is Select Website_Name from Website where lower(Website_Name)='wikipedia' And if i use utf8_unicode_ci then my select query to search wikipedia in Website is Select Website_Name from Website where Website_Name='wikipedia' Now I want to know which collation is best depending upon the following queries 回答1: It depends on

问题 I'm using Entity Framework 4.1 database first approach. I've used legacy database. In my edmx file which created entity classes based on tables in the legacy database, there is a one-to-zero-or-one association between some entities. Although I explored the tables of database and relation between them I didn't find out how one-to-zero-or-one relation have been implemented in database. For more information I put some screenshots of my database diagram and the property of its relation and

问题 I have table Lang: id | lang_name Table2: Messages: id | message_code Table3: Dictionary id | message_id | lang_id | translation I want to bring to the gridview with languages. Format: message_code | en_translation | ..._translation |..._translation As the number of languages is not known, i pass value of columns in array to gridview. There is one problem: I need to pass the value of the language id to relation model. I do not know how. $searchModel = new langmessages_search(); $dataProvider