lazy-loading

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 5 years ago . All I understand about lazy loading is that it loads only when the object is needed and we should use it. Please explain me which scenarios we have to use and not use it? Thanks in advance. 回答1: I would put it this way: Lazy loading is the essence of ORM. It is the principle of

问题 I am using jQuery Lazy Load to load thumbnails on a page I have a list of about 100+ thumbnails per page. This plug-in works perfect, until I introduce the plug-in Quick Pagination to display nine thumbnails at a time and give users the next and previous. When one clicks on the Next or Previous, you get the gray placeholder image as the page Scroll is no longer a factor. I tried different events and even created my own, this only loads all thumbnails even the ones below the threshold in the

问题 I expect to get only one sql query, but I run into the N+1 select trap. I don't really understand why. Here is is the problem in detail: I have an entity "PlayerRef": @Entity @Table(name = "player_ref") public class PlayerRef { //constructor etc... @OptimisticLock(excluded = true) @OneToMany(fetch = FetchType.LAZY, mappedBy = "playerRef") public Set<Player> getPlayers() { return players; } } And a class Player: @Entity @Table(name = "player") public class Player { //constructor etc...

问题 I have application structure like this: 1. app 1. Shared Module 2. Modules 1. ExternalSourceModule Child Modules 1. SourceModule 2. EntityModule ExternalSourceSharedModule ExternalSourceSharedModule imports SharedModule because shared module has application level dependencies ExternalSourceModule and it child modules imports ExternalSourceSharedModule because ExternalSourceSharedModule has some dependencies which ExternalSourceModule and it's Child Modules Needs Code of

问题 The relation between Product and Customer is of type many-to-many (from a design point a view). Using EF Core, we split this relation in two one-to-many relations with a third entity: ProductCustomer public partial class ProductCustomer { public long ProductId { get; set; } public long CustomerId { get; set; } public virtual Customer Customer { get; set; } public virtual Product Product { get; set; } public virtual ICollection<UsageRecord> UsageRecord { get; set; } } UsageRecord is a list of

问题 I have two ng-module Dash Board Repeat order list I had loaded Repeat order through the lazy load. Now I want to use Repeat order, inside dashboard as html <app-repeatorderlist></app-repeatorderlist> If I am doing same it is throwing me an error 'app-repeatorderlist' is not a known element: 1. If 'app-repeatorderlist' is an Angular component, then verify that it is part of this module. 2. If 'app-repeatorderlist' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas'

问题 In the function below, after the context.SaveChanges(), the entity PropertyType is always null. I just converted from using ObjectContext to DBContext (with database first) and before the change, it worked fine and now it doesn't. Is there something I'm missing? I check the PropertyTypeID and it is written correctly and exists in the db. All relationships are correctly setup in the db and edmx file. The generated .tt files show the PropertyType object as virtual. This is EF 5. Here is the

问题 consider this scenario: I have loaded a Parent entity through hibernate Parent contains a collection of Children which is large and lazy loaded The hibernate session is closed after this initial load while the user views the Parent data The user may choose to view the contents of the lazy Children collection I now wish to load that collection What are the ways / best way of loading this collection? Assume session-in-view is not an option as the fetching of the Children collection would only

问题 I am trying to develop spring rest api with hibernate. after searching in google, I have not find solution to lazy loading. I have two entity like below: University.java @Entity() @Table(schema = "core", name = "university") public class University extends BaseEntity { private String uniName; private String uniTelephon; @LazyCollection(LazyCollectionOption.FALSE) @OneToMany(fetch = FetchType.LAZY, mappedBy = "university", cascade = CascadeType.ALL) @JsonManagedReference private List<Student>

问题 I'm designing a multi-tiered database driven web application – SQL relational database, Java for the middle service tier, web for the UI. The language doesn't really matter. The middle service tier performs the actual querying of the database. The UI simply asks for certain data and has no concept that it's backed by a database. The question is how to handle large data sets? The UI asks for data but the results might be huge, possibly too big to fit in memory. For example, a street sign